using System;

​

public class Program

{

    public delegate int Sum3Numbers(int a1, int a2, int a3);

    static void Main(string[] args)

    {

        Sum3Numbers sumFunc = delegate (int a, int b, int c)

        {

            return a + b + c;

        };

        int result = sumFunc(1, 2, 3);

        Console.WriteLine(result);

    }

}