class PrimeNumberGenerator {
 public:
  explicit PrimeNumberGenerator(int start) : start_(start) {}
  int GetNextPrime() {
    int temp = start_;
    if (is_first) {
      for (int i = 2; i <= start_; i++) {
        if (i == start_) {
          is_first = false;
          return start_;
        }
        if (temp % i == 0) {
          break;
        }
      }
    }
    is_first = false;
    while (true) {
      temp++;
      bool flag = false;
      for (int i = 2; i <= temp; i++) {
        if (i == temp) {
          flag = true;
          break;
        }
        if (temp % i == 0) {
          break;
        }
      }
      if (flag) {
        start_ = temp;
        break;
      }
    }
    return start_;
  }

 private:
  bool is_first = true;
  int start_;
};