#include <iostream>

auto isPrime(int, int) -> bool;

auto main(int argc, char** argv) -> int {
    int toCheck = 0;

    while(std::cin >> toCheck) {
        if(isPrime(toCheck, 2)) std::cout << "true" << std::endl;
        else std::cout << "false" << std::endl;
    }

    return 0;
}


auto isPrime(int n, int i) -> bool {
    if(n <= 2) return (n == 2) ? true : false;
    if(!(n%i)) return false;
    if(i*i > n) return true;

    return isPrime(n, i+1);
}