using System;

public class Program

{

    public static void Main(string[] args)

    {

        Console.WriteLine(test(53));

            Console.WriteLine(test(30));

            Console.WriteLine(test(51));

            Console.ReadLine();

        }

​

          public static int test(int n)

        {

            const int x = 51;

​

            if (n > x)

            {

                return (n - x)*3;

            }

            return x - n;

    }

}