using System;

​

public class Maths

{

    public int a;

    public int c;

    public int h;

}

​

public class Output

{

    public static void Main(int[] args)

    {

        Maths Maths = new Maths();

        Maths.a = 10;

        Maths.c = 50;

        Maths.h = 100;

        int S = ((Maths.a + Maths.c) * Maths.h) / 2;

        Console.WriteLine("S = {0}",S);

    }

}