#include <iostream>
using namespace std;

int main() {

    // write your code here......
    long long int n;
    cin>>n;
    if(n<=1){
    	return 0;
	}
    for(int i=1;i<=n/2;i++){
        for(int j=1;j<=i;j++){
            if(i*j==n){
                cout<<"不是质数"<<endl;
                return 0;
            }
        }
    }
    cout<<"是质数"<<endl;

    return 0;
}