import java.security.MessageDigest;

/**
 * @author /u/Philboyd_Studge
 */
public class Advent4 {

    public static boolean check(byte[] b, boolean part1) {
        return (b[0] | b[1] | (part1 ? (b[2] >> 4 & 0xf) : b[2])) == 0;
    }

    public static void main(String[] args) throws Exception {

        MessageDigest md = MessageDigest.getInstance("MD5");
        String test = "ckczppom";
        int pad = 1;
        long time = System.currentTimeMillis();
        while (true) {
            byte[] md5 = md.digest((test + pad++).getBytes());
            if (check(md5, false)) break;                         // true for part1, false for part2
        }
        System.out.println(pad - 1);
        System.out.println("Time: " + (System.currentTimeMillis() - time));
    }
}