using System;

using System.Threading;

using System.Collections.Generic;

​

public class Program

{

    class X

    {

        (int,int) pt;

        public X()

        {

            pt = (1,2);

        }

        public (int,int) F() => pt;

        public override string ToString() => $"{pt.Item1},{pt.Item2}";

    }

    public static void Main()

    {

        X x = new X();

        var pt = x.F();

        pt.Item1++;

        Console.Write(x);

    }

}