#27532:
#include <iostream>
using namespace std;
int main(){
int n;
while (cin >> n){
if (n%3==0){
cout <<"YES"<<endl;
}
else {
cout <<"NO"<<endl;
}
}
}
ZeroJudge Forum
#include <iostream>
using namespace std;
int main(){
int n;
while (cin >> n){
if (n%3==0){
cout <<"YES"<<endl;
}
else {
cout <<"NO"<<endl;
}
}
}