还好，有点坑

#include<bits/stdc++.h>
using namespace std;

int main(){
int n,b;
cin>>n;
if(n%21){
cout<<"NO";
return 0;
}
b=n/2;
if(b%20&&b>0){
cout<<"YES";
}
else{
cout<<"NO";
}
return 0;
}