AC

#include<iostream>
using namespace std;
int is_prime(int n)
{
if (n1)
return 0;
for (int i=2;i*i<=n;i++)
if (n%i0)
return 0;
return 1;
}
int main() {

int n;
cin >> n;
if(is_prime(n)) cout << "Yes" << endl;
else cout << "No" << endl;

return 0;
}