diff --git a/README.md b/README.md
index bd90ef0247..084826964a 100644
--- a/README.md
+++ b/README.md
@@ -1 +1,5 @@
-# java-calculator-precourse
\ No newline at end of file
+# java-calculator-precourse
+
+문자열을 받아서 덧셈 구현
+숫자끼리 합을 구해 결과 도출
+커스텀 구분자 지정 가능
\ No newline at end of file
diff --git a/src/main/java/calculator/Application.java b/src/main/java/calculator/Application.java
index 573580fb40..9734208cb4 100644
--- a/src/main/java/calculator/Application.java
+++ b/src/main/java/calculator/Application.java
@@ -1,7 +1,23 @@
 package calculator;
 
+import static camp.nextstep.edu.missionutils.Console.readLine;
+
 public class Application {
     public static void main(String[] args) {
-        // TODO: 프로그램 구현
+        Parse parse = new Parse();
+        Calculator calculator = new Calculator(parse);
+        while(true) {
+            System.out.println("덧셈할 문자열을 입력해 주세요. 종료를 원하시면 0을 입력해 주세요.");
+            String input = readLine();
+            if (input.isEmpty()) {
+                continue;
+            }
+            if (input.charAt(0) == '0') {
+                System.out.println("종료합니다.");
+                break;
+            }
+            int output = calculator.getOutput(input);
+            System.out.println("결과 : " + output);
+        }
     }
-}
+}
\ No newline at end of file
diff --git a/src/main/java/calculator/Calculator.java b/src/main/java/calculator/Calculator.java
new file mode 100644
index 0000000000..66e0a52a45
--- /dev/null
+++ b/src/main/java/calculator/Calculator.java
@@ -0,0 +1,33 @@
+package calculator;
+
+public class Calculator {
+    private final Parse parse;
+
+    public Calculator(Parse parse) {
+        this.parse = parse;
+    }
+
+    public int getOutput(String input) {
+        int i = parse.parseCustom(input);
+        int result;
+        result = calculate(input,i);
+
+        return result;
+    }
+
+    public int calculate(String input, int i) {
+        int output = 0;
+        for (; i<input.length(); i++) {
+            if (parse.getCustom().contains(input.charAt(i))) {
+                output += parse.parseInteger();
+            } else if (input.charAt(i) >= '0' && input.charAt(i) <= '9') {
+                parse.addValue(input.charAt(i));
+            } else {
+                System.out.println("숫자, 구분자 이외 문자 입력. 애플리케이션 종료.");
+                throw new IllegalArgumentException("숫자, 구분자 이외 문자 입력. 애플리케이션 종료.");
+            }
+        }
+        output += parse.parseInteger();
+        return output;
+    }
+}
diff --git a/src/main/java/calculator/Parse.java b/src/main/java/calculator/Parse.java
new file mode 100644
index 0000000000..868f2fd407
--- /dev/null
+++ b/src/main/java/calculator/Parse.java
@@ -0,0 +1,56 @@
+package calculator;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class Parse {
+    private final List<Character> custom;
+    private final StringBuilder value = new StringBuilder();
+
+    public Parse() {
+        custom = new ArrayList<>();
+        custom.add(',');
+        custom.add(':');
+    }
+    public List<Character> getCustom() {
+        return custom;
+    }
+
+    public int parseCustom(String input) {
+        if (input.length() < 5) {
+            return 0;
+        }
+        if (input.charAt(0) == '/') {
+            if (input.charAt(1) != '/') {
+                System.out.println("/만 나오므로 종료.");
+                throw new IllegalArgumentException("/만 나오므로 종료");
+            }
+            if (input.charAt(3) != '\\') {
+                System.out.println("//이후 \\이 나오지 않아 종료.");
+                throw new IllegalArgumentException("//이후 \\이 나오지 않아 종료");
+            }
+            if (input.charAt(4) != 'n') {
+                System.out.println("\\이후 n이 나오지 않아 종료.");
+                throw new IllegalArgumentException("\\이후 n이 나오지 않아 종료");
+            }
+            if (!(custom.contains(input.charAt(2)))) {
+                custom.add(input.charAt(2));
+            }
+            return 5;
+        }
+        return 0;
+    }
+
+    public int parseInteger() {
+        int result = 0;
+        if (!(value.isEmpty())) {
+            result = Integer.parseInt(value.toString());
+        }
+        value.setLength(0);
+        return result;
+    }
+
+    public void addValue(char c) {
+        value.append(c);
+    }
+}