program ct;
uses crt;
var T,V:real;
begin
clrscr;
write('nhap diem toan=');readln(T);
write('nhap diem van=');readln(V);
if (T+V)>=18 then writeln('Gioi');
if (T+V)>=16 and (T+V)<18 then writeln('kha');
if (T+V)>=12 and (T+V)<16 then writeln('trung binh');
if (T+V)<12 then writeln('yeu');
readln
end.