#include <iostream>
using namespace std;

int main() {
    int n;
    // write your code here......
    cin >> n;
    bool flag = 0;
    for (int i = 2; i < n; i++) {
        if (n % i == 0) {
            flag = 1;
            break;
        }

    }
    if (flag == 1) {
        cout << "不是质数";
    } else{
        cout << "是质数";
    }

        return 0;
}