diff --git a/Graph/DFS.cpp b/Graph/DFS.cpp
new file mode 100644
index 00000000..d60ceaaf
--- /dev/null
+++ b/Graph/DFS.cpp
@@ -0,0 +1,27 @@
+#include<bits/stdc++.h>
+#define pb push_back
+using namespace std;
+const int LIM = 50;
+int vis[LIM];
+vector<vector<int> >AdjList(LIM);
+void dfs(int u){
+	cout<<u<<" , ";
+	vis[u]=1;
+	for(auto v:AdjList[u]){
+		if(vis[v]==0){
+			dfs(v);
+		}
+	}
+}
+int main(){
+	int n,m;
+	cin>>n>>m;
+	for(int i=0;i<m;i++){
+		int u,v;
+		cin>>u>>v;
+		AdjList[u].pb(v);
+		AdjList[v].pb(u);
+	}
+	dfs(1);
+
+}
\ No newline at end of file
diff --git a/Maths/EulerGCD.cpp b/Maths/EulerGCD.cpp
new file mode 100644
index 00000000..a2921575
--- /dev/null
+++ b/Maths/EulerGCD.cpp
@@ -0,0 +1,18 @@
+#include<bits/stdc++.h>
+using namespace std;
+int iterativeGcd(int a,int b){
+	while(a!=0){
+		int rem = b%a;
+		b = a;
+		a = rem;
+	}
+	return b;
+}
+int recursiveGcd(int a, int b){
+	if(a==0)return b;
+	return recursiveGcd(b%a,a);
+}
+int main(){
+	int a = 6,b=4;
+	cout<<recursiveGcd(a,b);
+}
diff --git a/Maths/FastExponentiation.cpp b/Maths/FastExponentiation.cpp
new file mode 100644
index 00000000..4041dd00
--- /dev/null
+++ b/Maths/FastExponentiation.cpp
@@ -0,0 +1,30 @@
+#include<bits/stdc++.h>
+#define ll long long
+using namespace std;
+ll fastExpo(ll base, ll power){
+	if(power==0)
+		return 1;
+	ll temp = fastExpo(base,power/2);
+	if(power&1){
+		return temp*temp * base;
+	}
+	return temp*temp;
+}
+ll fastExpoIterative(ll base, ll power){
+	ll res = 1;
+	while(power	>0){
+		if(power&1){
+			res*=base;
+		}
+		power/=2;
+		base*=base;
+	}
+	return res;
+
+}
+int main(){	
+	ll base = 5;
+	ll power = 3;
+	cout<<fastExpoIterative(base,power);
+
+}
\ No newline at end of file
diff --git a/Searching/BinarySearch.cpp b/Searching/BinarySearch.cpp
new file mode 100644
index 00000000..1593eecb
--- /dev/null
+++ b/Searching/BinarySearch.cpp
@@ -0,0 +1,36 @@
+#include<bits/stdc++.h>
+using namespace std;
+//Create a predicate to return T/F for an ind
+bool predicate(vector<int>&v, int ind, int search_token){
+	return v[ind] >= search_token;
+}
+int binarySeach(vector<int>&v, int search_token){
+	int low = 0,high = v.size(),mid;
+	while(low<high){
+		mid = (low+high)/2;
+		if(predicate(v,mid,search_token)){
+			high = mid;
+		}
+		else
+			low = mid+1;
+	}
+	if(v[low]==search_token) return low;
+	return -1;
+}
+int recursiveBinarySearch(vector<int>&v, int search_token, int begin, int end){
+	if(begin==end){
+		if(v[begin]==search_token)
+			return begin;
+		return -1;
+	}
+	int mid = (begin+end)/2;
+	if(predicate(v,mid,search_token)){
+		return recursiveBinarySearch(v,search_token,begin,mid);
+	}
+	return recursiveBinarySearch(v,search_token,mid+1,end);
+}
+int main(){
+	vector<int> v = {1,2,4,5,11,20,25};
+	cout<<recursiveBinarySearch(v,6,0,6);
+	return 0;
+}
\ No newline at end of file
diff --git a/Sorting/BubbleSort.java b/Sorting/BubbleSort.java
new file mode 100644
index 00000000..6932c335
--- /dev/null
+++ b/Sorting/BubbleSort.java
@@ -0,0 +1,34 @@
+public class BubbleSortExample {  
+    static void bubbleSort(int[] arr) {  
+        int n = arr.length;  
+        int temp = 0;  
+        for(int i=0; i < n; i++){  
+            for(int j=1; j < (n-i); j++){  
+                if(arr[j-1] > arr[j]){  
+                         //swap elements  
+                         temp = arr[j-1];  
+                         arr[j-1] = arr[j];  
+                         arr[j] = temp;  
+                }  
+                      
+             }  
+         }
+    }  
+    public static void main(String[] args) {  
+        int arr[] ={3,60,35,2,45,320,5};  
+         
+        System.out.println("Array Before Bubble Sort");  
+        for(int i=0; i < arr.length; i++){  
+                System.out.print(arr[i] + " ");  
+        }  
+        System.out.println();  
+          
+        bubbleSort(arr);//sorting array elements using bubble sort  
+         
+        System.out.println("Array After Bubble Sort");  
+        for(int i=0; i < arr.length; i++){  
+                System.out.print(arr[i] + " ");  
+        }  
+   
+    }  
+}  
diff --git a/Sorting/HeapSort.cpp b/Sorting/HeapSort.cpp
new file mode 100644
index 00000000..2d1d46fe
--- /dev/null
+++ b/Sorting/HeapSort.cpp
@@ -0,0 +1,40 @@
+#include<bits/stdc++.h>
+#define sz(v) ((int)v.size())
+using namespace std;
+void heapify(vector<int>&v, int SIZE, int ind){
+	int left_child = (ind<<1)+1;
+	int right_child = left_child+1;
+	int to_swap;
+	if(left_child<SIZE && v[left_child] > v[ind])
+		to_swap = left_child;
+	else
+		to_swap = ind;
+	if(right_child<SIZE && v[right_child] > v[to_swap])
+		to_swap = right_child;
+	if(to_swap !=ind){
+		int temp = v[to_swap];
+		v[to_swap] = v[ind];
+		v[ind] = temp;
+		heapify(v,SIZE,to_swap);
+	}
+}
+void heapSort(vector<int>&v){
+	vector<int>heap(sz(v));
+	for(int i=(sz(v)-2)/2;i>=0;i--){
+		heapify(v,sz(v),i);
+	}
+	for(int i=sz(v)-1;i>0;i--){
+		int temp = v[0];
+		v[0] = v[i];
+		v[i] = temp;
+
+		heapify(v,i,0);
+	}
+}
+int main(){
+	vector<int>temp = {1,3,2,12,444,5};
+	heapSort(temp);
+	for(int v:temp){
+		cout<<v<<" ";
+	}
+}
\ No newline at end of file
diff --git a/Sorting/LinearSort.cpp b/Sorting/LinearSort.cpp
new file mode 100644
index 00000000..78e61d92
--- /dev/null
+++ b/Sorting/LinearSort.cpp
@@ -0,0 +1,21 @@
+#include<bits/stdc++.h>
+using namespace std;
+void linearSort(vector<int>&v){
+	for(int i=0;i<v.size();i++){
+		for(int j=i+1;j<v.size();j++){
+			if(v[j]<v[i]){
+				int temp = v[i];
+				v[i] = v[j];
+				v[j] = temp;
+			}
+		}
+		
+	}
+}
+int main(){
+	vector<int>temp = {1,3,2,12,444,5};
+	linearSort(temp);
+	for(int v:temp){
+		cout<<v<<" ";
+	}
+}
\ No newline at end of file
diff --git a/Sorting/MergeSort.cpp b/Sorting/MergeSort.cpp
new file mode 100644
index 00000000..188a36ad
--- /dev/null
+++ b/Sorting/MergeSort.cpp
@@ -0,0 +1,33 @@
+#include<bits/stdc++.h>
+using namespace std;
+void merge(vector<int>&v, int startIndex, int mid, int endIndex){
+	vector<int>temp;
+	int i1 = startIndex;
+	int i2 = mid+1;
+	while(i1<=mid && i2<=endIndex){
+		if(v[i1]<=v[i2])
+			temp.push_back(v[i1]),i1++;
+		else
+			temp.push_back(v[i2]),i2++;
+	}
+	while(i1<=mid)temp.push_back(v[i1]),i1++;
+	while(i2<=endIndex)temp.push_back(v[i2]),i2++;
+	for(int i=0;i<temp.size();i++)
+		v[startIndex+i] = temp[i];
+}
+void mergeSort(vector<int>&v, int startIndex, int endIndex){
+	if(startIndex<endIndex){
+		int mid = (startIndex+endIndex)/2;
+		mergeSort(v,startIndex,mid);
+		mergeSort(v,mid+1,endIndex);
+		merge(v,startIndex,mid,endIndex);	
+	}
+	
+}
+int main(){
+	vector<int>temp = {1,3,2,12,444,5};
+	mergeSort(temp,0, temp.size()-1);
+	for(int v:temp){
+		cout<<v<<" ";
+	}
+}
\ No newline at end of file
diff --git a/Sorting/SelectionSort.py b/Sorting/SelectionSort.py
new file mode 100644
index 00000000..ba1b5d37
--- /dev/null
+++ b/Sorting/SelectionSort.py
@@ -0,0 +1,27 @@
+# Selection sort takes n-1 passes to complete
+# During every iteration index of minimum number/string is found in the innermost loop and then swapped once it comes out of that loop
+# No flag like improvised Bubble Sort so even if we put sorted list it is still going to take O(n^2) time complexity
+# Worst Time Complexity: O(n^2)
+# Average Time Complexity: O(n^2)
+# Best Time Complexity: O(n^2)
+
+print("Number Sequence Before Selection Sort")
+seq=[5,2,1,8,3,5,3]
+print(seq)
+
+def selectionSort(nums):
+    n=len(nums)
+    for i in range(n-1):
+        iMin=i
+        for j in range(i+1,n):
+            if(nums[iMin]>nums[j]):
+                iMin=j
+        temp=nums[i]
+        nums[i]=nums[iMin]
+        nums[iMin]=temp
+    return nums
+
+print("Number Sequence After Selection Sort")
+print(selectionSort(seq))
+
+
diff --git a/ascii-char_cpp b/ascii-char_cpp
new file mode 100644
index 00000000..697d3356
--- /dev/null
+++ b/ascii-char_cpp
@@ -0,0 +1,10 @@
+// CPP program to print 
+// ASCII Value of Character 
+#include <iostream> 
+using namespace std; 
+int main() 
+{ 
+    char c = 'A'; 
+    cout << "The ASCII value of " << c << " is " << int(c); 
+    return 0; 
+} 
diff --git a/cf/1550b b/cf/1550b
new file mode 100644
index 00000000..50d93a84
--- /dev/null
+++ b/cf/1550b
@@ -0,0 +1,42 @@
+#include<bits/stdc++.h>
+#define ll          long long int
+#define loop(i,a,b) for(int (i)=(a);(i)<(b);(i)++)
+#define rep(i,n)    for(int (i)=0;(i)<n;(i)++)
+#define bp          1000000007
+#define sz(a)       int((a).size())
+#define pb          push_back
+#define mp          make_pair
+#define all(c)      (c).begin(),(c).end()
+#define F           first
+#define S           second
+using namespace std;
+typedef pair<ll,ll> ii;
+void solve(){
+	int n,a,b;
+	cin>>n>>a>>b;
+	string s;
+	cin>>s;
+	vector<int>c(2,0);
+	c[s[0]-'0']++;
+	for(int i=1;i<sz(s);i++){
+		if(s[i]!=s[i-1]){
+			c[s[i]-'0']++;
+		}
+	}
+	int ans = a*n;
+	if(b>0)
+		ans += b*n;
+	else
+		ans += b*(min(c[0],c[1])+1);
+	cout<<ans<<endl;
+}
+int main(){
+	ios_base::sync_with_stdio(0);
+	cin.tie(0);
+	cout.tie(0);
+	int t;
+	cin>>t;
+	while(t--)
+	solve();
+	return 0;
+}
diff --git a/cf/fourth.cpp b/cf/fourth.cpp
new file mode 100644
index 00000000..d8e404fd
--- /dev/null
+++ b/cf/fourth.cpp
@@ -0,0 +1,68 @@
+#include<bits/stdc++.h>
+#define ll          long long int
+#define loop(i,a,b) for(int (i)=(a);(i)<(b);(i)++)
+#define rep(i,n)    for(int (i)=0;(i)<n;(i)++)
+#define bp          1000000007
+#define sz(a)       int((a).size())
+#define pb          push_back
+#define mp          make_pair
+#define all(c)      (c).begin(),(c).end()
+#define F           first
+#define S           second
+using namespace std;
+typedef pair<ll,ll> ii;
+void solve(){
+	int n;
+	cin>>n;
+	vector<vector<int>>v(n,vector<int>(5,0));
+	rep(i,n){
+		rep(j,5){
+			cin>>v[i][j];
+		}
+	}
+	vector<int>w = v[0];
+	int ans=0;
+	bool exists=  false;
+
+	for(int i=1;i<n;i++){
+		int c=0,c2=0;
+		rep(j,5){
+			if(v[i][j] < w[j])c++;
+			else if(v[i][j] > w[j])c2++;
+		}
+		if(c>=3 || c2>=3)exists = true;
+		if(c>=3){
+			w = v[i];
+			ans = i;
+		}
+	}
+	if(n > 1 && !exists){
+		cout<<-1<<endl;
+		return;
+	}
+
+	rep(i,n){
+		if(i!=ans){
+			int c=0;
+			rep(j,5){
+				if(v[i][j] > w[j])c++;
+			}
+			if(c < 3){
+				cout<<-1<<endl;
+				return;
+			}
+		}
+	}
+	cout<<ans+1<<endl;
+
+}
+int main(){
+	ios_base::sync_with_stdio(0);
+	cin.tie(0);
+	cout.tie(0);
+	int t = 1;
+	cin>>t;
+	while(t--)
+		solve();
+	return 0;
+}
diff --git a/cf/second.cpp b/cf/second.cpp
new file mode 100644
index 00000000..ef8187e0
--- /dev/null
+++ b/cf/second.cpp
@@ -0,0 +1,74 @@
+#include<bits/stdc++.h>
+#define ll          long long int
+#define loop(i,a,b) for(int (i)=(a);(i)<(b);(i)++)
+#define rep(i,n)    for(int (i)=0;(i)<n;(i)++)
+#define bp          1000000007
+#define sz(a)       int((a).size())
+#define pb          push_back
+#define mp          make_pair
+#define all(c)      (c).begin(),(c).end()
+#define F           first
+#define S           second
+using namespace std;
+typedef pair<ll,ll> ii;
+bool p(int k, vector<int>&v1, vector<int>&v2){
+	int x = (k-sz(v1));
+	int canTake = k-k/4;
+	int take = min(canTake, x);
+	int s1 = take*100 + v1[canTake-take-1];
+	int s2 = canTake < sz(v2) ? v2[canTake-1] : v2.back();
+	return s1>=s2;
+}
+void solve(){
+	int n;
+	cin>>n;
+	vector<int>v1(n);
+	rep(i,n){
+		cin>>v1[i];
+	}
+
+	vector<int>v2(n);
+	rep(i,n){
+		cin>>v2[i];
+	}
+	sort(all(v1));
+	reverse(all(v1));
+	sort(all(v2));
+	reverse(all(v2));
+	for(int i=1;i<n;i++){
+		v1[i] += v1[i-1];
+		v2[i] += v2[i-1];
+	}
+	// rep(i,n)cout<<v1[i]<<",";
+	// cout<<endl;
+	// rep(i,n)cout<<v2[i]<<",";
+	// cout<<endl;
+	int low=n;
+	int high = 2*n;
+	int mid;
+	while(low<high){
+		mid = (low+high)/2;
+		// cout<<mid<<","<< p(mid,v1,v2)<<endl;
+		if(p(mid, v1, v2)){
+			high = mid;
+		}
+		else{
+			low = mid+1;
+		}
+	}
+	cout<<low-n<<endl;
+}
+int main(){
+	ios_base::sync_with_stdio(0);
+	cin.tie(0);
+	cout.tie(0);
+	int t = 1;
+	cin>>t;
+	while(t--)
+		solve();
+	return 0;
+}
+// 1
+// 4
+// 20 30 40 50
+// 100 100 100 100
diff --git a/cf/third.cpp b/cf/third.cpp
new file mode 100644
index 00000000..c6c138a0
--- /dev/null
+++ b/cf/third.cpp
@@ -0,0 +1,67 @@
+#include<bits/stdc++.h>
+#define ll          long long int
+#define loop(i,a,b) for(int (i)=(a);(i)<(b);(i)++)
+#define rep(i,n)    for(int (i)=0;(i)<n;(i)++)
+#define bp          1000000007
+#define sz(a)       int((a).size())
+#define pb          push_back
+#define mp          make_pair
+#define all(c)      (c).begin(),(c).end()
+#define F           first
+#define S           second
+using namespace std;
+typedef pair<int,int> ii;
+void solve(){
+	int n;
+	cin>>n;
+	map<int,int>m;
+	vector<int>a(n);
+	vector<int>ans(n);
+	rep(i,n)cin>>a[i],m[a[i]]++;
+	vector<int>v;
+	int cnt=0;
+	rep(i,n){
+        if(m.find(i+1) == m.end()){
+            v.push_back(i+1);
+        }
+	}
+	rep(i,n){
+        if(m[a[i]] > 1){
+            m[a[i]]--;
+            ans[i] = v.back();
+            v.pop_back();
+        }
+        else{
+            ans[i] = a[i];
+            cnt++;
+        }
+	}
+	//either there is 1 self mapping or none
+	rep(i,n){
+        if(ans[i] == i+1){
+
+            rep(j,n){
+                if(ans[j] == a[i]){
+                    ans[j] = i+1;
+                    break;
+                }
+            }
+            ans[i] = a[i];
+            break;
+        }
+    }
+    cout<<cnt<<endl;
+    rep(i,n)cout<<ans[i]<<" ";
+    cout<<endl;
+}
+int main(){
+	ios_base::sync_with_stdio(0);
+	cin.tie(0);
+	cout.tie(0);
+	int test=1;
+	cin>>test;
+	while(test--){
+		solve();
+	}
+	return 0;
+}
diff --git a/codeforces/1530c.cpp b/codeforces/1530c.cpp
new file mode 100644
index 00000000..ef8187e0
--- /dev/null
+++ b/codeforces/1530c.cpp
@@ -0,0 +1,74 @@
+#include<bits/stdc++.h>
+#define ll          long long int
+#define loop(i,a,b) for(int (i)=(a);(i)<(b);(i)++)
+#define rep(i,n)    for(int (i)=0;(i)<n;(i)++)
+#define bp          1000000007
+#define sz(a)       int((a).size())
+#define pb          push_back
+#define mp          make_pair
+#define all(c)      (c).begin(),(c).end()
+#define F           first
+#define S           second
+using namespace std;
+typedef pair<ll,ll> ii;
+bool p(int k, vector<int>&v1, vector<int>&v2){
+	int x = (k-sz(v1));
+	int canTake = k-k/4;
+	int take = min(canTake, x);
+	int s1 = take*100 + v1[canTake-take-1];
+	int s2 = canTake < sz(v2) ? v2[canTake-1] : v2.back();
+	return s1>=s2;
+}
+void solve(){
+	int n;
+	cin>>n;
+	vector<int>v1(n);
+	rep(i,n){
+		cin>>v1[i];
+	}
+
+	vector<int>v2(n);
+	rep(i,n){
+		cin>>v2[i];
+	}
+	sort(all(v1));
+	reverse(all(v1));
+	sort(all(v2));
+	reverse(all(v2));
+	for(int i=1;i<n;i++){
+		v1[i] += v1[i-1];
+		v2[i] += v2[i-1];
+	}
+	// rep(i,n)cout<<v1[i]<<",";
+	// cout<<endl;
+	// rep(i,n)cout<<v2[i]<<",";
+	// cout<<endl;
+	int low=n;
+	int high = 2*n;
+	int mid;
+	while(low<high){
+		mid = (low+high)/2;
+		// cout<<mid<<","<< p(mid,v1,v2)<<endl;
+		if(p(mid, v1, v2)){
+			high = mid;
+		}
+		else{
+			low = mid+1;
+		}
+	}
+	cout<<low-n<<endl;
+}
+int main(){
+	ios_base::sync_with_stdio(0);
+	cin.tie(0);
+	cout.tie(0);
+	int t = 1;
+	cin>>t;
+	while(t--)
+		solve();
+	return 0;
+}
+// 1
+// 4
+// 20 30 40 50
+// 100 100 100 100
diff --git a/codeforces/1530d.cpp b/codeforces/1530d.cpp
new file mode 100644
index 00000000..c6c138a0
--- /dev/null
+++ b/codeforces/1530d.cpp
@@ -0,0 +1,67 @@
+#include<bits/stdc++.h>
+#define ll          long long int
+#define loop(i,a,b) for(int (i)=(a);(i)<(b);(i)++)
+#define rep(i,n)    for(int (i)=0;(i)<n;(i)++)
+#define bp          1000000007
+#define sz(a)       int((a).size())
+#define pb          push_back
+#define mp          make_pair
+#define all(c)      (c).begin(),(c).end()
+#define F           first
+#define S           second
+using namespace std;
+typedef pair<int,int> ii;
+void solve(){
+	int n;
+	cin>>n;
+	map<int,int>m;
+	vector<int>a(n);
+	vector<int>ans(n);
+	rep(i,n)cin>>a[i],m[a[i]]++;
+	vector<int>v;
+	int cnt=0;
+	rep(i,n){
+        if(m.find(i+1) == m.end()){
+            v.push_back(i+1);
+        }
+	}
+	rep(i,n){
+        if(m[a[i]] > 1){
+            m[a[i]]--;
+            ans[i] = v.back();
+            v.pop_back();
+        }
+        else{
+            ans[i] = a[i];
+            cnt++;
+        }
+	}
+	//either there is 1 self mapping or none
+	rep(i,n){
+        if(ans[i] == i+1){
+
+            rep(j,n){
+                if(ans[j] == a[i]){
+                    ans[j] = i+1;
+                    break;
+                }
+            }
+            ans[i] = a[i];
+            break;
+        }
+    }
+    cout<<cnt<<endl;
+    rep(i,n)cout<<ans[i]<<" ";
+    cout<<endl;
+}
+int main(){
+	ios_base::sync_with_stdio(0);
+	cin.tie(0);
+	cout.tie(0);
+	int test=1;
+	cin>>test;
+	while(test--){
+		solve();
+	}
+	return 0;
+}
diff --git a/codeforces/1550b.cpp b/codeforces/1550b.cpp
new file mode 100644
index 00000000..50d93a84
--- /dev/null
+++ b/codeforces/1550b.cpp
@@ -0,0 +1,42 @@
+#include<bits/stdc++.h>
+#define ll          long long int
+#define loop(i,a,b) for(int (i)=(a);(i)<(b);(i)++)
+#define rep(i,n)    for(int (i)=0;(i)<n;(i)++)
+#define bp          1000000007
+#define sz(a)       int((a).size())
+#define pb          push_back
+#define mp          make_pair
+#define all(c)      (c).begin(),(c).end()
+#define F           first
+#define S           second
+using namespace std;
+typedef pair<ll,ll> ii;
+void solve(){
+	int n,a,b;
+	cin>>n>>a>>b;
+	string s;
+	cin>>s;
+	vector<int>c(2,0);
+	c[s[0]-'0']++;
+	for(int i=1;i<sz(s);i++){
+		if(s[i]!=s[i-1]){
+			c[s[i]-'0']++;
+		}
+	}
+	int ans = a*n;
+	if(b>0)
+		ans += b*n;
+	else
+		ans += b*(min(c[0],c[1])+1);
+	cout<<ans<<endl;
+}
+int main(){
+	ios_base::sync_with_stdio(0);
+	cin.tie(0);
+	cout.tie(0);
+	int t;
+	cin>>t;
+	while(t--)
+	solve();
+	return 0;
+}
diff --git a/codeforces/1552b.cpp b/codeforces/1552b.cpp
new file mode 100644
index 00000000..d8e404fd
--- /dev/null
+++ b/codeforces/1552b.cpp
@@ -0,0 +1,68 @@
+#include<bits/stdc++.h>
+#define ll          long long int
+#define loop(i,a,b) for(int (i)=(a);(i)<(b);(i)++)
+#define rep(i,n)    for(int (i)=0;(i)<n;(i)++)
+#define bp          1000000007
+#define sz(a)       int((a).size())
+#define pb          push_back
+#define mp          make_pair
+#define all(c)      (c).begin(),(c).end()
+#define F           first
+#define S           second
+using namespace std;
+typedef pair<ll,ll> ii;
+void solve(){
+	int n;
+	cin>>n;
+	vector<vector<int>>v(n,vector<int>(5,0));
+	rep(i,n){
+		rep(j,5){
+			cin>>v[i][j];
+		}
+	}
+	vector<int>w = v[0];
+	int ans=0;
+	bool exists=  false;
+
+	for(int i=1;i<n;i++){
+		int c=0,c2=0;
+		rep(j,5){
+			if(v[i][j] < w[j])c++;
+			else if(v[i][j] > w[j])c2++;
+		}
+		if(c>=3 || c2>=3)exists = true;
+		if(c>=3){
+			w = v[i];
+			ans = i;
+		}
+	}
+	if(n > 1 && !exists){
+		cout<<-1<<endl;
+		return;
+	}
+
+	rep(i,n){
+		if(i!=ans){
+			int c=0;
+			rep(j,5){
+				if(v[i][j] > w[j])c++;
+			}
+			if(c < 3){
+				cout<<-1<<endl;
+				return;
+			}
+		}
+	}
+	cout<<ans+1<<endl;
+
+}
+int main(){
+	ios_base::sync_with_stdio(0);
+	cin.tie(0);
+	cout.tie(0);
+	int t = 1;
+	cin>>t;
+	while(t--)
+		solve();
+	return 0;
+}
diff --git a/mirror inverse_java b/mirror inverse_java
new file mode 100644
index 00000000..0f7c3b8c
--- /dev/null
+++ b/mirror inverse_java	
@@ -0,0 +1,28 @@
+// Java implementation of the approach 
+public class GFG { 
+  
+    // Function that returns true if 
+    // the array is mirror-inverse 
+    static boolean isMirrorInverse(int arr[]) 
+    { 
+        for (int i = 0; i < arr.length; i++) { 
+  
+            // If condition fails for any element 
+            if (arr[arr[i]] != i) 
+                return false; 
+        } 
+  
+        // Given array is mirror-inverse 
+        return true; 
+    } 
+  
+    // Driver code 
+    public static void main(String[] args) 
+    { 
+        int arr[] = { 1, 2, 3, 0 }; 
+        if (isMirrorInverse(arr)) 
+            System.out.println("Yes"); 
+        else
+            System.out.println("No"); 
+    } 
+}