#include <bits/stdc++.h>
using namespace std;
double a,b,c,tb;
int main()
{
cin>>a>>b>>c;
tb=((a+b)*2+c)/5;
if (tb>=9) cout<<"Gioi";
else if ((tb>=7) and (tb<9)) cout<<"Kha";
else if ((tb>=5) and (tb<7)) cout<<"Trung binh";
else cout<<"Yeu";
return 0;
}