#include <cmath>

class PrimeNumberGenerator {
 public:
    explicit PrimeNumberGenerator(int start):
            prime_number(NearestPrime(start)) {}
    int GetNextPrime() {
        int buff = prime_number;
        prime_number = NearestPrime(prime_number + 1);
        return buff;
    }

 private:
    int prime_number;
    int NearestPrime(int n) {
        int i;
        for (i = n; !is_prime(i); i++) {}
        return i;
    }

    bool is_prime(int n) {
        if (n == 1)
            return false;
        if (n == 2)
            return true;
        for (int i = 2; i <= sqrt(n) + 1; i++)
            if (!(n % i))
                return false;
        return true;
    }
};