ACCODE

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