#include<iostream>
#include<cstdio>
using namespace std;

int main()
{
  double t1,t2;

  while(scanf("%lf %lf",&t1,&t2)!=EOF){

    if(t1<35.5 && t2<71.0)
      cout<<"AAA"<<endl;

    else if(t1<37.5 && t2<77.0)
      cout<<"AA"<<endl;

    else if(t1<40.0 && t2<83.0)
      cout<<"A"<<endl;

    else if(t1<43.0 && t2<89.0)
      cout<<"B"<<endl;

    else if(t1<50.0 && t2<105.0)
      cout<<"C"<<endl;

    else if(t1<55.0 && t2<116.0)
      cout<<"D"<<endl;

    else if(t1<70.0 && t2<148.0)
      cout<<"E"<<endl;

    else
      cout<<"NA"<<endl;
  }
}