diff --git a/src/main/java/gpacalc/Application.java b/src/main/java/gpacalc/Application.java
index 57e79e1..b4ad342 100644
--- a/src/main/java/gpacalc/Application.java
+++ b/src/main/java/gpacalc/Application.java
@@ -1,7 +1,61 @@
 package gpacalc;
 
+import java.util.List;
+
+
+// ...
+
+
 public class Application {
     public static void main(String[] args) {
         //TODO: 구현
+
+        // 1. 과목 - 학점 - 점수 묶음으로 입력
+
+        // 2. 형태에 맞춰 필요한 정보 담기 ( 제대로 담기만 하면 됨 )
+
+        // 3. parsing 후에 계산
+
+        // 4. 이쁘게 출력
+
+
+//      1. (완료)
+
+
+        Input input = new Input();
+        String majorScore = input.getMajorInput();
+        String elecScore = input.getElectiveInput();
+
+
+//      2. (완료)
+
+        ParseString parseString = new ParseString();
+        List<String> majorResult = parseString.getSeparated(majorScore);
+        List<String> elecResult = parseString.getSeparated(elecScore);
+
+
+//      3. (완료)
+
+        System.out.println("<과목 목록>");
+        Calculator calculator = new Calculator();
+        calculator.initializeNumbers();
+        calculator.calculateMajorInputIntoGPA(majorResult);
+        calculator.printMajorInput(majorResult);
+        calculator.calculateElecInputIntoGPA(elecResult);
+        calculator.printElecInput(elecResult);
+
+//      4. (완료)
+
+        calculator.printSum();
+        calculator.printAverageOfAll();
+        calculator.printAverageOfMajor(calculator.calculateMajorInputIntoGPA(majorResult));
+
+
+//데이타구조-3-A0,자바프로그래밍언어-3-B+,컴퓨터구조-3-C0,컴퓨터네트워크-3-D+
+//미술의이해-3-P,교양특론3-1-NP,기독교의이해-2-F
+
+
+        System.out.println("=== [System] : 계산이 끝났습니다. ===");
+
     }
 }
diff --git a/src/main/java/gpacalc/Calculator.java b/src/main/java/gpacalc/Calculator.java
new file mode 100644
index 0000000..0e5dda7
--- /dev/null
+++ b/src/main/java/gpacalc/Calculator.java
@@ -0,0 +1,367 @@
+package gpacalc;
+
+import java.util.Arrays;
+import java.util.List;
+
+public class Calculator {
+
+
+    private double totalScore;
+    private double majorTotalScore;
+    private double majorSum;
+    private double elecSum;
+
+    private double grade;
+    private double credit;
+    private double rate;
+
+    private final int minScore = 1;
+    private final int maxScore = 4;
+
+    private final int maxLength = 10;
+
+
+    public void printMajorInput(List<String> infoMaj) {
+
+        for (int i = 0; i < infoMaj.size(); i++) {
+            if (i % 3 == 0) {
+                System.out.print("[전공] ");
+                checkNamingException(infoMaj.get(i));
+            }
+            System.out.print(infoMaj.get(i) + ",");
+
+            if (i % 3 == 1) {
+                credit = Integer.parseInt(infoMaj.get(i));
+                checkScoreException(credit);
+
+
+            } else if (i % 3 == 2) {
+                System.out.println();
+                checkRateException(infoMaj.get(i));
+
+
+            }
+        }
+
+    }
+
+    public double calculateMajorInputIntoGPA(List<String> infoMaj) {
+
+
+        for (int i = 0; i < infoMaj.size(); i++) {
+            if (i % 3 == 0) {
+                checkNamingException(infoMaj.get(i));
+            }
+
+
+            if (i % 3 == 1) {
+                credit = Integer.parseInt(infoMaj.get(i));
+                checkScoreException(credit);
+                calculateTotalScore(infoMaj.get(i + 1));
+                calculateTotalMajorScore(infoMaj.get(i + 1));
+            } else if (i % 3 == 2) {
+
+                checkRateException(infoMaj.get(i));
+                if (!infoMaj.get(i).equals("P") && !infoMaj.get(i).equals("NP")) {
+                    switch (infoMaj.get(i)) {
+                        case "A+":
+                            rate = 4.5;
+                            break;
+                        case "A0":
+                            rate = 4.0;
+                            break;
+                        case "B+":
+                            rate = 3.5;
+                            break;
+                        case "B0":
+                            rate = 3.0;
+                            break;
+                        case "C+":
+                            rate = 2.5;
+                            break;
+                        case "C0":
+                            rate = 2.0;
+                            break;
+                        case "D+":
+                            rate = 1.5;
+                            break;
+                        case "D0":
+                            rate = 1.0;
+                            break;
+                        case "F":
+                            rate = 0;
+                            break;
+                    }
+                    addMajorScore(credit, rate);
+                }
+            }
+        }
+        return majorSum / majorTotalScore;
+    }
+
+
+    public void printElecInput(List<String> infoElec) {
+
+        for (int i = 0; i < infoElec.size(); i++) {
+            if (i % 3 == 0) {
+                System.out.print("[교양] ");
+                checkNamingException(infoElec.get(i));
+            }
+            System.out.print(infoElec.get(i) + ",");
+
+
+
+            if (i % 3 == 1) {
+                credit = Integer.parseInt(infoElec.get(i));
+                checkScoreException(credit);
+
+
+
+
+            } else if (i % 3 == 2) {
+                System.out.println();
+                checkRateException(infoElec.get(i));
+
+            }
+        }
+
+    }
+
+    public double calculateElecInputIntoGPA(List<String> infoElec) {
+
+        for (int i = 0; i < infoElec.size(); i++) {
+            if (i % 3 == 0) {
+                checkNamingException(infoElec.get(i));
+            }
+
+            if (i % 3 == 1) {
+                credit = Integer.parseInt(infoElec.get(i));
+                checkScoreException(credit);
+
+                calculateTotalScore(infoElec.get(i + 1));
+
+            } else if (i % 3 == 2) {
+
+                checkRateException(infoElec.get(i));
+                if (!infoElec.get(i).equals("P") && !infoElec.get(i).equals("NP")) {
+                    switch (infoElec.get(i)) {
+                        case "A+":
+                            rate = 4.5;
+                            break;
+                        case "A0":
+                            rate = 4.0;
+                            break;
+                        case "B+":
+                            rate = 3.5;
+                            break;
+                        case "B0":
+                            rate = 3.0;
+                            break;
+                        case "C+":
+                            rate = 2.5;
+                            break;
+                        case "C0":
+                            rate = 2.0;
+                            break;
+                        case "D+":
+                            rate = 1.5;
+                            break;
+                        case "D0":
+                            rate = 1.0;
+                            break;
+                        case "F":
+                            rate = 0;
+                            break;
+                    }
+
+                    addElecScore(credit, rate);
+                }
+            }
+        }
+
+        return (majorSum + elecSum) / grade;
+    }
+
+    public void initializeNumbers() {
+        setTotalScore(0);
+        setMajorTotalScore(0);
+        setMajorSum(0);
+        setElecSum(0);
+        setGrade(0);
+    }
+
+    public boolean isRightScore(double userScore) {
+        boolean rightScore = true;
+
+        if (userScore < minScore || userScore > maxScore) {
+            rightScore = false;
+        }
+
+        return rightScore;
+    }
+
+
+    public boolean isWrongInput(String lectureName) {
+        boolean moreThanTen = true;
+
+        if (lectureName.isBlank() || lectureName.length() > maxLength) {
+            moreThanTen = false;
+        }
+
+        return moreThanTen;
+    }
+
+    public void calculateTotalMajorScore(String lectureType) {
+        if (!lectureType.equals("F") && !lectureType.equals("NP"))
+            majorTotalScore += credit;
+
+    }
+
+    public void calculateTotalScore(String lectureType) {
+        if (!lectureType.equals("F") && !lectureType.equals("NP"))
+            totalScore += credit;
+
+        if (!lectureType.equals("P") && !lectureType.equals("NP"))
+            grade += credit;
+    }
+
+
+    public void checkNamingException(String lectureName) {
+        try {
+            if (!isWrongInput(lectureName)) {
+                throw new IllegalArgumentException();
+            }
+        } catch (IllegalArgumentException e) {
+            System.out.println("\n === 올바르지 않은 과목명입니다. ===");
+            System.exit(0);
+        }
+    }
+
+    public void checkScoreException(double lectureScore) {
+        try {
+            if (!isRightScore(lectureScore)) {
+                throw new IllegalArgumentException();
+            }
+        } catch (IllegalArgumentException e) {
+            System.out.println("\n === 학점이 올바르지 않습니다. ===");
+            System.exit(0);
+        }
+    }
+
+    public void checkRateException(String userGrade) {
+        try {
+            if (hasRightScore(userGrade)) {
+                throw new IllegalArgumentException();
+            }
+        } catch (IllegalArgumentException e) {
+            System.out.println("\n === 성적이 올바르지 않습니다. ===");
+            System.exit(0);
+
+        }
+    }
+
+
+    public boolean hasRightScore(String score) {
+        boolean isRightScore = true;
+
+        if (Arrays.asList("A+", "A0", "B+", "B0", "C+", "C0", "D+", "D0", "F", "P", "NP").contains(score)) {
+            isRightScore = false;
+        }
+
+        return isRightScore;
+    }
+
+    public void printSum() {
+        System.out.println("\n <취득학점>");
+        System.out.println((int) totalScore + "학점");
+    }
+
+    private void addMajorScore(double score, double r) {
+        majorSum += score * r;
+
+    }
+
+    private void addElecScore(double score, double r) {
+        elecSum += score * r;
+
+    }
+
+    public void printAverageOfAll() {
+        double avg = (majorSum + elecSum) / grade;
+        System.out.println("<평점평균>");
+        System.out.println(String.format("%.2f / 4.5", avg));
+
+
+    }
+
+    public void printAverageOfMajor(double majorCalculateResult) {
+        System.out.println("<전공 평점평균>");
+        System.out.println(String.format("%.2f / 4.5", majorCalculateResult));
+    }
+
+
+
+
+
+
+
+
+
+
+    public double getTotalScore() {
+        return totalScore;
+    }
+
+    public void setTotalScore(double totalScore) {
+        this.totalScore = totalScore;
+    }
+
+    public double getMajorTotalScore() {
+        return majorTotalScore;
+    }
+
+    public void setMajorTotalScore(double majorTotalScore) {
+        this.majorTotalScore = majorTotalScore;
+    }
+
+    public double getMajorSum() {
+        return majorSum;
+    }
+
+    public void setMajorSum(double majorSum) {
+        this.majorSum = majorSum;
+    }
+
+    public double getElecSum() {
+        return elecSum;
+    }
+
+    public void setElecSum(double elecSum) {
+        this.elecSum = elecSum;
+    }
+
+    public double getGrade() {
+        return grade;
+    }
+
+    public void setGrade(double grade) {
+        this.grade = grade;
+    }
+
+    public double getCredit() {
+        return credit;
+    }
+
+    public void setCredit(double credit) {
+        this.credit = credit;
+    }
+
+    public double getRate() {
+        return rate;
+    }
+
+    public void setRate(double rate) {
+        this.rate = rate;
+    }
+
+}
diff --git a/src/main/java/gpacalc/Input.java b/src/main/java/gpacalc/Input.java
new file mode 100644
index 0000000..614423b
--- /dev/null
+++ b/src/main/java/gpacalc/Input.java
@@ -0,0 +1,25 @@
+package gpacalc;
+
+import static camp.nextstep.edu.missionutils.Console.readLine;
+
+import camp.nextstep.edu.missionutils.Console;
+
+
+public class Input {
+
+    public String getMajorInput(){
+
+        System.out.println(" ===  전공 과목명과 이수학점, 평점을 입력해주세요 === ");
+
+        String majorScore = Console.readLine();
+        return majorScore;
+    }
+
+    public String getElectiveInput(){
+
+        System.out.println(" ===  교양 과목명과 이수학점, 평점을 입력해주세요 === ");
+
+        String elecScore = Console.readLine();
+        return elecScore;
+    }
+}
diff --git a/src/main/java/gpacalc/ParseString.java b/src/main/java/gpacalc/ParseString.java
new file mode 100644
index 0000000..eb2a715
--- /dev/null
+++ b/src/main/java/gpacalc/ParseString.java
@@ -0,0 +1,22 @@
+package gpacalc;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+public class ParseString {
+
+    public List<String> getSeparated(String wholeInput) {
+
+        String[] splFirst = wholeInput.split(",");
+        List<String> resultList = new ArrayList<>();
+
+
+        for (String resultSplit : splFirst) {
+            String[] result = resultSplit.split("-");
+            resultList.addAll(Arrays.asList(result));
+        }
+
+        return resultList;
+    }
+}
diff --git a/src/test/java/gpacalc/CalculatorTest.java b/src/test/java/gpacalc/CalculatorTest.java
new file mode 100644
index 0000000..1118af1
--- /dev/null
+++ b/src/test/java/gpacalc/CalculatorTest.java
@@ -0,0 +1,84 @@
+package gpacalc;
+
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.*;
+
+class CalculatorTest {
+
+    //given
+    Calculator calculator;
+
+    @BeforeEach
+    void setUp() {
+        calculator = new Calculator();
+    }
+
+
+    @DisplayName("과목명 공백 검사")
+    @Test
+    void checkNamingException() {
+        //when
+        String lectureName = "    ";
+
+        //then
+        assertThrows(IllegalArgumentException.class, () -> {
+            calculator.checkNamingException(lectureName);
+        });
+    }
+
+    @DisplayName("학점 범위 검사")
+    @Test
+    void checkScoreException() {
+
+        //when
+        int score = 6;
+
+        //then
+        assertThrows(IllegalArgumentException.class, () -> {
+            calculator.checkScoreException(score);
+        });
+
+
+    }
+
+    @DisplayName("성적 범위 검사")
+    @Test
+    void checkRateException() {
+
+        //when
+        String grade = "E+";
+
+        //then
+        assertThrows(IllegalArgumentException.class, () -> {
+            calculator.checkRateException(grade);
+        });
+    }
+
+    @DisplayName("평점평균 계산")
+    @Test
+    void printAverageOfAll() {
+
+
+        List<String> lectureDump = Arrays.asList("데이타구조", "3", "A0", "자바프로그래밍언어", "3", "B+", "컴퓨터구조", "3", "C0",
+                "네트워크", "3", "D+", "미술의이해", "3", "P", "교양특론", "1", "NP", "기독교의 이해", "2", "F");
+
+        assertEquals(2.357142857142857, calculator.calculateElecInputIntoGPA(lectureDump));
+    }
+
+
+    @AfterEach
+    void tearDown() {
+        calculator = null;
+    }
+
+
+}
\ No newline at end of file