AC

#include<bits/stdc++.h>
using namespace std;
int main(){
int n;
cin >> n;
if (n <= 1){
cout << "No";
return 0;
}
bool flag = true;
for (int i = 2;i < n;i++){
if(n%i == 0){
flag = false;
break;
}
}
if(flag) cout << "Yes";
else cout << "No";
return 0;
}