#include <iostream>
using namespace std;

char rank[8][4] = {"AAA", "AA", "A", "B", "C", "D", "E", "NA"};
double aa[7] = {35.5, 37.5, 40.0, 43.0, 50.0, 55.0, 70.0};
double bb[7] = {71.0, 77.0, 83.0, 89.0, 105.0, 116.0, 148.0};

int main()
{
    double a,b;
    while(cin >> a >> b){
        for(int i=0;i<8;i++){
            if(i==7){
                cout << rank[i] << endl;
                break;
            }
            if(a < aa[i] && b < bb[i]){
                cout << rank[i] << endl;
                break;
            }
        }
    }
    return 0;
}