public static void Main() {
Console.WriteLine("a + b = " + (a + b));
Console.WriteLine("a - b = " + (a - b));
Console.WriteLine("a * b = " + (a * b));
Console.WriteLine("a / b = " + (a / b));
Console.WriteLine("a % b = " + (a % b));
Console.WriteLine("a++ = " + (a++));
Console.WriteLine("b-- = " + (b--));