using System;

public class Program

{

    public static void Main(string [] args)

    {

        //Arithmetic Operators

        int x = 5;

        int y = 4;

        Console.WriteLine(x-y);

        Console.WriteLine(x+y);

        //Increment and Decrement Operators

        x++;

        Console.WriteLine(x);

        x--;

        Console.WriteLine(x);

         //constants

        double PI = 3.14;

        Console.WriteLine(PI * 5 * 5);

        Console.WriteLine(PI * 5 + 5);

​

      //input and and output   

      Console.WriteLine("Enter a name:");

      string yourName= Console.ReadLine();

      Console.WriteLine("Your name is: " + yourName);

      Console.WriteLine("Enter a nickname:");

      string nickName= Console.ReadLine();

      Console.WriteLine("Your nickname is: " + nickName);

    }

}