* @param y
   * @return long
   */
  public static long gcd(long x, long y) {
    if (x < 0) {
      x = 0 - x;
    }
    if (y < 0) {
      y = 0 - y;
    }
    { long temp = 0l;

      while (!(y == 0)) {
        temp = (x % y);
        x = y;
        y = temp;
      }
      return (x);
    }
  }