using System;

public class Program

{

    public static void Main()

    {

        int p1 = 500;

        float x = 20;

        var xBytes = BitConverter.GetBytes(x);

        var p1Bytes = BitConverter.GetBytes(p1);

        var resultBytes = new byte[4];

        for(var i = 0; i < 4; i++) {

            int a = (int) xBytes[i];

            int b = (int) p1Bytes[i];

            resultBytes[i] = (byte) (a ^ b);

        }

        var result = BitConverter.ToSingle(resultBytes, 0);

        Console.WriteLine(result);

    }

}