using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

        var input = Console.ReadLine();

        var it =

            input.Split("+") switch {

                    [var l, var r] =>

                        (left: long.Parse(l), "+", right: long.Parse(r)),

                        _ => throw new Exception("Inte än"),

            };

        Console.WriteLine(it.left + it.right);

    }

}