HDU 1021

#include<iostream>
#include<cstdio>
using namespace std;
int a[1001000];
int main(){
int n;
a[0]=7;
a[1]=11;
while(scanf("%d",&n) != EOF){
for( int i=2;i<=n;++i)
{
a[i] = (a[i-1]+a[i-2])%3;
}
if(a
%3 == 0) cout<<"yes"<<endl;
else cout<<"no"<<endl;
}
return 0;
}