using System;

public class Program

{

    public static void Main()

    {

        bool rule1 = false;

        bool rule2 = false;

        Console.WriteLine("insert number one");

        int number1 = Int16.Parse(Console.ReadLine());

        Console.WriteLine("insert number two");

        int number2 = Int16.Parse(Console.ReadLine());

        Console.WriteLine("insert number three");

        int number3 = Int16.Parse(Console.ReadLine());

        if ((number1 + number2 + number3) %3 == 0){

        rule1 = true; 

        }

        if (number1 - number2 != 1 && number2 - number3 !=1 && number3 - number1 !=1){

        rule2 = true; 

        }

        if (rule1&&rule2){

            Console.WriteLine(Convert.ToString(number1)+Convert.ToString(number2)+Convert.ToString(number3)+" IS A VALID SITESWAP");

        }

        else {

                Console.WriteLine("INVALID SITESWAP");

    }

    }

}