#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <ctime>
#include <cassert>
#include <iostream>
#include <cctype>
#include <sstream>
#include <string>
#include <list>
#include <vector>
#include <queue>
#include <set>
#include <stack>
#include <map>
#include <utility>
#include <numeric>
#include <algorithm>
#include <iterator>
#include <bitset>
#include <complex>
#include <fstream>
using namespace std;
typedef long long ll;
const double EPS = 1e-9;
typedef vector<int> vint;
typedef pair<int, int> pint;
#define rep(i, n) REP(i, 0, n)
#define ALL(v) v.begin(), v.end()
#define MSG(a) cout << #a << " " << a << endl;
#define REP(i, x, n) for(int i = x; i < n; i++)
template<class T> T RoundOff(T a){ return int(a+.5-(a<0)); }
template<class T, class C> void chmax(T& a, C b){ if(a < b) a = b; }
template<class T, class C> void chmin(T& a, C b){ if(b < a) a = b; }


int light[] = {35.5, 37.5, 40, 43, 50, 55, 70};
int heavy[] = {71, 77, 83, 89, 105, 116};
string cls[] = {"AAA", "AA", "A", "B", "C", "D", "E"};


string comp(double a, double b)
{
	rep(i, 7)
		if(a < light[i] && b < heavy[i])
			return cls[i];
	
	return "NA";
}

int main()
{
    double a, b;
	while(cin >> a >> b)
		cout << comp(a, b) << endl;
}