using System;

public class Program

{

    public static void Main()

    {

double z,x,y;

int s;

Console.WriteLine("Enter x");

x=Convert.ToDouble(Console.ReadLine());

Console.WriteLine("Enter y");

y=Convert.ToDouble(Console.ReadLine());

Console.WriteLine("Enter s");

s=Convert.ToInt32(Console.ReadLine());

switch(s){

    case 1:z=Math.Pow(x,4)+y;

        Console.WriteLine("z="+z);

        break;

    case 2:z=Math.Pow(x,4)-y;

        Console.WriteLine("z="+z);

        break;

    case 3:z=Math.Pow(x,4)*y;

        Console.WriteLine("z="+z);

        break;  

    case 4:z=Math.Pow(x,4)/y;

        Console.WriteLine("z="+z);

        break;

    default: Console.WriteLine("error of enter s");

        break;

}       

​

    }

}