using System;

​

interface computation

{

    int add(int x, int y);

}

​

class app : computation

{

    public int add(int x, int y)

    {

        return x * y;

    }

}

​

public class demo

{

    public static void Main(String[] args)

    {

        app a = new app();

        int b = a.add(10, 6);

        Console.WriteLine(b);

    }

}