#include <iostream> #include <vector> #include <algorithm> using namespace std; bool is_prime(int n) { static vector<int> primes{2, 3, 5}; if (n < 1) return false; if (n > primes.back()) { for (int i = primes.back() + 2; i <= n; i++) { bool is_prime = std::all_of(pri...