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