import java.util.*;
import java.lang.*;
public class Main
{
public static void main(String[] args) {
Scanner s = new Scanner(System.in);
Players[] players = new Players[4];
for(int i=0; i<players.length; i++){
int id = s.nextInt();s.nextLine();
String name = s.nextLine();
int exp = s.nextInt();
int matchesPlayed = s.nextInt();
int runsScored = s.nextInt();
players[i] = new Players(id, name, exp, matchesPlayed, runsScored);
}
int target = s.nextInt();
double avgRuns[] = calculateAvg(players, target);
for(int i=0; i<avgRuns.length; i++){
if(avgRuns[i]>=80 && avgRuns[i]<=100)
System.out.println("Grade A");
else if(avgRuns[i]>=50)
System.out.println("Grade B");
else
System.out.println("Grade C");
}
}
public static double[] calculateAvg(Players[] obj, int target){
double arr[];
int j = 0;
for(int i=0; i<obj.length; i++){
if(obj[i].getMatchesPlayed()<=target)
j+=1;
}
arr = new double[j];
j = 0;
for(int i=0; i<obj.length;i++){
if(obj[i].getMatchesPlayed()<=target)
arr[i] = (double) (obj[i].getRunsScored()/obj[i].getMatchesPlayed());
}
return arr;
}
}
class Players{
int id;
String name;
int exp;
int matchesPlayed;
int runsScored;
public Players(int id, String name, int exp, int matchesPlayed, int runsScored){
this.id = id;
this.name = name;
this.exp = exp;
this.matchesPlayed = matchesPlayed;
this.runsScored = runsScored;
}
public int getId(){
return id;
}
public String getName(){
return name;
}
public int getExp(){
return exp;
}
public int getMatchesPlayed(){
return matchesPlayed;
}
public int getRunsScored(){
return runsScored;
}
}
