#include<iostream>
#include<cstdio>
#include<cmath>
#include<cstring>
#include<string>
#include<stack>
#include<queue>
#include<vector>
typedef long long int ll;
using namespace std;
#define FOR(i,a,b) for (int i=(a);i<=(b);i++)
    int N,a,b;
    int zero;
    int one;
    std::vector<int> SOSU;
 int main(){
     ios_base::sync_with_stdio(false);
     one++;
     cin>>N;
     if(N==one){
         cout<<"NO"<<endl;
         return zero;
     }
     one++;
     FOR(i,one,N){
         if(!(SOSU.size())){
             SOSU.push_back(i);
             continue;
         }
         for(auto x:SOSU){
             if(!(i%x))break;
             if(x==SOSU.back()){
                 SOSU.push_back(i);

             }
         }

     }
     if(SOSU.back()==N)cout<<"YES"<<endl;
     else cout<<"NO"<<endl;
return zero;
 }