diff --git a/src/App.java b/src/App.java
index 0a839f9..afd3518 100644
--- a/src/App.java
+++ b/src/App.java
@@ -1,5 +1,44 @@
+import java.util.InputMismatchException;
+import java.util.Scanner;
+
 public class App {
     public static void main(String[] args) throws Exception {
-        System.out.println("Hello, World!");
+        Scanner input = new Scanner(System.in);
+        boolean flag = true;
+        while (flag) {
+            try{
+                System.out.println("------------------------------------\n" +
+                        "    Please select operation:\n" +
+                        "\t1- C   to  F\n" +
+                        "\t2- F   to  C\n" +
+                        "   SELECT ANY OTHER NUMBER TO QUIT\n");
+                double num;
+                switch (input.nextShort()) {
+                    case 1:
+                        num = takeNum();
+                        displayNum(num, (num * 9 / 5.0 + 32));
+                        break;
+                    case 2:
+                        num = takeNum();
+                        displayNum(num, ((num - 32) * 5 / 9.0));
+                        break;
+                    default:
+                        flag = false;
+                }
+            }
+            catch(InputMismatchException e){
+                System.err.println("Error: Input is of an incorrect datatype!");
+                input.nextLine();
+            }
+        }
+
     }
-}
+    static double takeNum() throws InputMismatchException {
+        System.out.print("Please insert number: ");
+        return new Scanner(System.in).nextDouble();
+    }
+
+    static void displayNum(double source, double conv){
+        System.out.printf("%.2f\t->\t%.2f\n", source, conv);
+    }
+}
\ No newline at end of file