using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("enter choice");

        int Choice = int.Parse(Console.ReadLine());

        int a=10,b=15;

        switch(Choice)

        {

            case 1:

                Console.WriteLine(a+b);

                break;

            case 2:

                Console.WriteLine(a-b);

                break;

            case 3: 

                Console.WriteLine(a*b);

                break;

            case 4: 

                Console.WriteLine(a>b);

                break;  

            default:

                Console.WriteLine("enetr valid choice");

                break;  

        }

        Console.ReadLine();     

    }

}