swap 2 integers without using temporary variable
using System;
class MainClass {
public static void Main (string[] args) {
int num1 = int.Parse(Console.ReadLine());
int num2 = int.Parse(Console.ReadLine());
num1 = num1 + num2;
num2 = num1 - num2;
num1 = num1 - num2;
Console.WriteLine("After swapping: num1 = "+ num1 + ", num2 = " + num2);
Console.ReadLine();
}
}