class PrimeNumberGenerator {
 private:
    int64_t number_start;

 public:
    explicit PrimeNumberGenerator(int64_t start) {
        this->number_start = start;
    }

    int GetNextPrime() {
        bool check;
        if (this->number_start == 2)
            return this->number_start++;
        if (this->number_start <2) this->number_start++;
        for (int i = this->number_start; i < 2 * this->number_start; i++) {
            check = true;
            for (int j = 2; j <= sqrt(i); j++) {
                if (i % j == 0) {
                    check = false;
                    break;
                }
            }
            if (check) {
                this->number_start = i + 1;
                return i;
            }
        }
        return 0;
    }
};