#include <iostream>
using namespace std;
typedef long long ll;
bool isPrime(ll n)
{
    if (n==1) return true;
    for(ll i=2;i*i<=n;++i)
        if (n%i==0) return false;
    return true;
}
int main()
{
    ll n;
    while (cin>>n) cout<<(isPrime(n) ? "NO" : "YES")<<endl;
}