diff --git a/.history/Marwa-Abdelmonem_20250628151717.md b/.history/Marwa-Abdelmonem_20250628151717.md
new file mode 100644
index 0000000..e69de29
diff --git a/.history/Marwa-Abdelmonem_20250628151726.md b/.history/Marwa-Abdelmonem_20250628151726.md
new file mode 100644
index 0000000..7fdce42
--- /dev/null
+++ b/.history/Marwa-Abdelmonem_20250628151726.md
@@ -0,0 +1,7 @@
+#include <iostream>
+using namespace std;
+int main()
+{
+    int n; cin>>n;
+    cout<< (n * (n-1)) / 2;
+}
\ No newline at end of file
diff --git a/.lh/.lhignore b/.lh/.lhignore
new file mode 100644
index 0000000..1de5100
--- /dev/null
+++ b/.lh/.lhignore
@@ -0,0 +1,6 @@
+# list file to not track by the local-history extension. comment line starts with a '#' character
+# each line describe a regular expression pattern (search for 'Javascript regex')
+# it will relate to the workspace directory root. for example:
+# '.*\.txt' ignores any file with 'txt' extension
+# '/test/.*' ignores all the files under the 'test' directory
+# '.*/test/.*' ignores all the files under any 'test' directory (even under sub-folders)
diff --git a/.lh/Marwa-Abdelmonem.md.json b/.lh/Marwa-Abdelmonem.md.json
new file mode 100644
index 0000000..e72532d
--- /dev/null
+++ b/.lh/Marwa-Abdelmonem.md.json
@@ -0,0 +1,18 @@
+{
+    "sourceFile": "Marwa-Abdelmonem.md",
+    "activeCommit": 0,
+    "commits": [
+        {
+            "activePatchIndex": 0,
+            "patches": [
+                {
+                    "date": 1751113046342,
+                    "content": "Index: \n===================================================================\n--- \n+++ \n"
+                }
+            ],
+            "date": 1751113046342,
+            "name": "Commit-0",
+            "content": "#include <iostream>\r\nusing namespace std;\r\nint main()\r\n{\r\n    int n; cin>>n;\r\n    cout<< (n * (n-1)) / 2;\r\n}"
+        }
+    ]
+}
\ No newline at end of file
diff --git a/Marwa-Abdelmonem.md b/Marwa-Abdelmonem.md
new file mode 100644
index 0000000..7fdce42
--- /dev/null
+++ b/Marwa-Abdelmonem.md
@@ -0,0 +1,7 @@
+#include <iostream>
+using namespace std;
+int main()
+{
+    int n; cin>>n;
+    cout<< (n * (n-1)) / 2;
+}
\ No newline at end of file