#include<cstdio>
#include<string>
main(){
        using namespace std;
        int i,j;
        string lv[8] = {"AAA","AA","A","B","C","D","E","NA"};
        double lvd5[7] = {35.5,37.5,40.0,43.0,50.0,55.0,70.0};
        int lvd1[7] = {71,77,83,89,105,116,148};
        double ind1,ind2;
        while(~scanf("%lf %lf",&ind1,&ind2)){
                i = j = 0;
                while(i<7){
                        if(ind1 < lvd5[i])
                                break;
                        i++;
                }
                while(j<7){
                        if(ind2 < lvd1[j])
                                break;
                        j++;
                }
                printf("%s\n", i <= j ? lv[i].c_str() : lv[j].c_str());
        }
        return 0;
}