纯代码

#include <iostream>
using namespace std;
int main() {
	int n;
    cin >> n;
    if(n % 3 == 0)cout << "3" << " ";
    if(n % 5 == 0)cout << "5" << " ";
    if(n % 7 == 0)cout << "7" << " ";
    else if(n % 3 != 0 && n % 5 != 0 && n % 7 != 0)cout << 'n';
	return 0;
}

拜拜~