Go: package main

import (
	"bufio"
	"os"
	"strings"
	"strconv"
	"fmt"
)

var scanner = bufio.NewScanner(os.Stdin)

func main() {
	m500 := []float64{35.5, 37.5, 40.0, 43.0, 50.0, 55.0, 70.0, 1000.0}
	m1000 := []float64{71.0, 77.0, 83.0, 89.0, 105.0, 116.0, 148.0, 1000.0}
	classes := []string{"AAA", "AA", "A", "B", "C", "D", "E", "NA"}
	for scanner.Scan() {
		input := strings.Split(scanner.Text(), " ")
		t500, _ := strconv.ParseFloat(input[0], 64)
		t1000, _ := strconv.ParseFloat(input[1], 64)
		for i := 0; i < len(m500); i++ {
			if t500 < m500[i] && t1000 < m1000[i] {
				fmt.Println(classes[i])
				break
			}
		}
	}
}

C++: //include
//------------------------------------------
#include <vector>
#include <list>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <ctime>
#include <fstream>
#include <complex>
#include <math.h>

using namespace std;

//conversion
//------------------------------------------
inline long toLong(string s) {long v; istringstream sin(s);sin>>v;return v;}
template<class T> inline string toString(T x) {ostringstream sout;sout<<x;return sout.str();}

//math
//-------------------------------------------
template<class T> inline T sqr(T x) {return x*x;}

//typedef
//------------------------------------------
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef pair<long, long> PLL;
typedef long long LL;
//container util
//------------------------------------------
#define ALL(a)  (a).begin(),(a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define PB push_back
#define MP make_pair
#define SZ(a) int((a).size())
#define EACH(i,c) for(typeof((c).begin()) i=(c).begin(); i!=(c).end(); ++i)
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define SORT(c) sort((c).begin(),(c).end())

//repetition
//------------------------------------------
#define FOR(i,a,b) for(long i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)

//constant
//--------------------------------------------

//clear memory
#define CLR(a) memset((a), 0 ,sizeof(a))

const long double EPS = 1e-12;
const double INF = 1e9;

struct edge{int to,cost;};
typedef pair<int,int> P;//firstは最短距離,secondは頂点番号


int main(){
	double a,b;
	string rnk[]={"AAA","AA","A","B","C","D","E","NA"};
	double m5[]={35.5,37.5,40.0,43.0,50.0,55.0,70.0,INF};
	double m10[]={71.0,77.0,83.0,89.0,105.0,116.0,148.0,INF};
	vector<string>res;
	while(cin>>a>>b){
		REP(i,8){
			if(a<m5[i]&&b<m10[i]){
				res.PB(rnk[i]);
				break;
			}
		}
	}
	REP(i,SZ(res))cout<<res[i]<<endl;
	return 0;
}

C++: #include<iostream>
#include<cstdio>
#include<algorithm>
#include<climits>
#include<string>
#include<vector>
#include<list>
#include<map>
#include<set>
#include<cmath>
#include<queue>
#include<cstring>
#include<stack>
#include<functional>
using namespace std;

int main(){
	double t1[7] = {35,37,40,43,50,55,70}, t2[7] = {71,77,83,89,105,116,148};
	double R1,R2;
	while(cin>>R1>>R2){
		int c1=7,c2=7;
		for(int i=6;i>=0;i--){
			if(R1<t1[i]) c1 = i;
			if(R2<t2[i]) c2 = i;
		}
		int c = max(c1,c2);
		if(c==0) puts("AAA");
		else if(c==1) puts("AA");
		else if(c==2) puts("A");
		else if(c==3) puts("B");
		else if(c==4) puts("C");
		else if(c==5) puts("D");
		else if(c==6) puts("E");
		else puts("NA");
	}
}

C++: #include<iostream>
#include<algorithm>
#include<vector>
#include<stack>
#include<map>
#include<set>
#include<queue>
#include<cstdio>
#include<climits>
#include<cmath>
#include<cstring>
#include<string>
#include<sstream>

#define f first
#define s second
#define mp make_pair

#define REP(i,n) for(int i=0; i<(int)(n); i++)
#define FOR(i,c) for(__typeof((c).begin()) i=(c).begin(); i!=(c).end(); i++)
#define ALL(c) (c).begin(), (c).end()

using namespace std;

typedef unsigned int uint;
typedef long long ll;

int chk500[8]={
  35, 37, 40, 43, 50, 55, 70, INT_MAX
};
int chk1000[8]={
  71, 77, 83, 89, 105, 116, 248, INT_MAX
};
const char *rank[8]={
  "AAA","AA","A","B","C","D","E","NA"
};

int main(){
  double a,b;
  while(~scanf("%lf%lf",&a,&b)){
    REP(i,8){
      if(a < (double)chk500[i] && b < (double)chk1000[i]){
        puts(rank[i]);
        break;
      }
    }
  }
  return 0;
}

C++: #include <bits/stdc++.h>
#define log(x) cout<<x<<endl
#define pb push_back
#define rep(i, n) for(int i = 0; i < (int)(n); i++)
#define all(x) (x).begin(),(x).end()
typedef long long lint;
using namespace std;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
const long long INF = 1LL << 60;

int gcd(lint x, lint y){
  return y==0 ? x:gcd(y,x % y);
}

int digsum(int n) {
  int res = 0;
  while(n > 0) {
    res += n%10;
    n /= 10;
  }
  return res;
}

int dignum(int n) {
  int res = 0;
  while(n > 0) {
    res++;
    n /= 10;
  }
  return res;
}

int stringcount(string s, char c) {
  return count(s.cbegin(), s.cend(), c);
}

int lcm(lint x, lint y){
  return x/ gcd(x, y) * y;
}

int combi(int n, int r){
  int num = 1;
  for(int i = 1; i <= r; i++){
    num = num * (n - i + 1) / i;
  }
  return num;
}

int main(){
  bool is=true;
  while(is){
    double a,b;
    cin>>a>>b;
    if(cin.eof()){
      is=false;
      break;
    }
    if(a<35.50&&b<71.00) cout<<"AAA"<<endl;
    else if(a<37.50&&b<77.00) cout<<"AA"<<endl;
    else if(a<40.00&&b<83.00) cout<<"A"<<endl;
    else if(a<43.00&&b<89.00) cout<<"B"<<endl;
    else if(a<50.00&&b<105.00) cout<<"C"<<endl;
    else if(a<55.00&&b<116.00) cout<<"D"<<endl;
    else if(a<70.00&&b<148.00) cout<<"E"<<endl;
    else cout<<"NA"<<endl;
  }
  return 0;
}

C++: #include <map>
#include <set>
#include <list>
#include <cmath>
#include <queue>
#include <stack>
#include <cstdio>
#include <string>
#include <vector>
#include <complex>
#include <cstdlib>
#include <cstring>
#include <numeric>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <functional>

#define mp       make_pair
#define pb       push_back
#define all(x)   (x).begin(),(x).end()
#define rep(i,n) for(int i=0;i<(n);i++)
#define repi(i,a,b) for(int i = (a); i < (b); i++)

using namespace std;

typedef    long long          ll;
typedef    unsigned long long ull;
typedef    vector<bool>       vb;
typedef    vector<int>        vi;
typedef    vector<vb>         vvb;
typedef    vector<vi>         vvi;
typedef    pair<int,int>      pii;

const int INF=1<<29;
const double EPS=1e-9;

const int dx[]={1,0,-1,0},dy[]={0,-1,0,1};
double table5[7]={35.50,37.50,40.0,43.0,50.0,55.0,70};
double table1[7]={71.0,77.0,83.0,89.0,105.0,116.0,148.0};
string score[7]={"AAA","AA","A","B","C","D","E"};
int main(){
	double a,b;
	while(cin>>a>>b){
		int t5 = 100;
		int t1 = 100;
		for(int i =0;i < 7;i++){
			if(a<table5[i]){
				t5 = i;
				break;
			}
		}
		for(int j =0;j < 7;j++){
			if(b<table1[j]){
				t1 =j;
				break;
			}
		}
		int ans = max(t1,t5);
		if(ans==100){
			cout <<"NA"<<endl;
		}else{
			cout <<score[ans]<<endl;
		}
	}
	return 0;
}

C++: #include<cstdio>
#include<cmath>
#include<iostream>
#include<algorithm>
using namespace std;
int main(){
    double A,B;
    while(cin>>A>>B){
        if(A<35.5&&B<71.0)puts("AAA");
        else if(A<37.5&&B<77.0)puts("AA");
        else if(A<40.0&&B<83.0)puts("A");
        else if(A<43.0&&B<89.0)puts("B");
        else if(A<50.0&&B<105.0)puts("C");
        else if(A<55.0&&B<116.0)puts("D");
        else if(A<70.0&&B<148.0)puts("E");
        else puts("NA");
    }
    return 0;
}