#include <iostream>

using namespace std;

int main() {

	double ms, ml;
	double s[7]={35.50, 37.50, 40.00, 43.00, 50.00, 55.00, 70.00};
	double l[7]={71.00, 77.00, 83.00, 89.00, 105.00, 116.00, 148.00};
	char r[8][4]={"AAA", "AA", "A", "B", "C", "D", "E", "NA"};

	while(cin >> ms >> ml) {
		int ss=7, ll=7;
		for(int i=6; i>=0; i--) {
			if(ms<s[i]) {
				ss=i;
			}
		}
		for(int i=6; i>=0; i--) {
			if(ml<l[i]) {
				ll=i;
			}
		}

		if(ss<ll) {
			ss=ll;
		}

		cout << r[ss] << endl;
	}
	
	return 0;

}