using System;

public class Program

{

    public static void Main()

    {

{

​

{

double z, x, y;

Console.Write("x=");

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

Console.Write("y=");

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

if (x * x - (y * y) > 0)

{

z = 0.978 + Math.Log(x * x - (y * y));

Console.WriteLine(z);

}

else if (x * x - (y * y) < 0)

{

z = (x * x - (y * y)) / Math.Pow(x,1.5);

Console.WriteLine(z);

}

else if (x * x - (y * y) == 0)

{

z = Math.Cos(x * x - (y * y));

Console.WriteLine(z);

}

}

}

        Console.WriteLine("z is");

    }

}