Something

package ConsoleApplication1;

import java.math.BigInteger;

public class Program
{
	public static void main(String[] args)
	{
		BigInteger a = new BigInteger("1");
		BigInteger b = new BigInteger(new byte[] { (byte)0x1 });
		BigInteger c = new BigInteger(new byte[] { (byte)0x1 });
		String str = new String("");

		while (true)
		{
			str = c.toString();

			if (str.Contains("31337"))
			{
				System.out.println("Encontrado: " + str);
				break;
			}
			
			c = a.add(b);
            a = c;
			b = a.subtract(b);
		}
	}
}