diff --git a/src/crypto/Crypto.java b/src/crypto/Crypto.java
index 51d57b7..04b2cb0 100644
--- a/src/crypto/Crypto.java
+++ b/src/crypto/Crypto.java
@@ -3,8 +3,36 @@
 import java.util.Scanner;
 
 public class Crypto {
+    private static void encryption(String message, int key) {
+        char let;
+        char let2;
+        StringBuilder str = new StringBuilder(message);
+        for (int i=0; i<str.length(); i++){
+            let = str.charAt(i);
+            let2=(char)(let+key);
+                str.setCharAt(i, let2);}
+        System.out.println(str);
+    }
+    private static void decryption(String message, int key) {
+        char let;
+        char let2;
+        StringBuilder str = new StringBuilder(message);
+        for (int i=0; i<str.length(); i++){
+            let = str.charAt(i);
+            let2=(char)(let-key);
+            str.setCharAt(i, let2);}
+        System.out.println(str);
+    }
+
     public static void main(String[] args) {
-        Scanner scanner = new Scanner(System.in);
-	// write your code here
+        Scanner scan = new Scanner(System.in);
+        String target = scan.nextLine();
+        String message = scan.nextLine();
+        int key = scan.nextInt();
+        if (target.equals("enc")) {
+            encryption(message, key);
+        }
+        else if (target.equals("dec")) decryption(message, key);
+
     }
 }