using System;

​

public class Program

{

    static long factorial(long n)

    {

        long fact = 1;

        for (long i = 2; i <= n; i++)

            fact = fact * i;

        return fact;

    }

​

    // calculate c(n, r)  

    static long ncr(long n, long r)

    {

        return factorial(n) / (factorial(r) * factorial(n - r));

    }

​

    // Driver code  

    public static void Main()

    {

        long m = 10, n = 8;

        long totalTriangles = ncr(m + n, 3) - ncr(m, 3) - ncr(n, 3);

        Console.WriteLine(totalTriangles);

    }

}