#include<iostream>
#include<iomanip>
#include<string>
#include<algorithm>
#include<vector>
#include<set>
#include<list>
#include<queue>
#include<math.h>
#include<bitset>
using ll = long long;
using namespace std;

int main(){
    ll n;
    cin >> n;
    vector<ll> prime(n+1, 1);
    prime[0] = 0;
    for (int i = 2; i <= pow(n, 0.5); i++){
        for (int j = i+i; j <= n; j += i) prime[j] = 0;
    }
    cout << ((prime[n]) ? "NO" : "YES") << endl;
}