public Unknown(String in) {
      this.digits = in.toCharArray();
      char[] max = new char[digits.length];

      boolean free = false;
      for (int x = 0; x < digits.length; x++) {
        if (digits[x] == '?') {
          max[x] = '9';
          free = true;
        } else {
          max[x] = digits[x];
        }
      }
      maxvalue = Integer.parseInt(new String(max));
      
      if (free) {
        finalvalue = -1;
      } else {
        finalvalue = maxvalue;
      }
    }