using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace PregatireExamen {
    class Swaping {
        public void swap(ref int x, ref int y) {
            int a, b; a = x; b = y; swap2(ref a, ref b);
        }
        public void swap2(ref int a, ref int b) {
            int temp; temp = a; a = b; b = a;
        }
        static void Main(string[] args) {
            Swaping n = new Swaping();
            int a = 100;
            int b = 200;
            n.swap(ref a, ref b);
            Console.WriteLine(a+" "+b);
        }
    }
}