import java.util.*;
import java.lang.*;
import java.io.*;
class Main {
public static void main(String[] args) {
Scanner s=new Scanner(System.in);
int a=s.nextInt();
int b=s.nextInt();
if((a==1 && b==3)||(!(a==1&&b==3)&&(a>b))){
System.out.println('A');
}else{
System.out.println('B');
}
}
}
a,b=map(int,input().split())
if a==1 and b==3 or ((not (a==1 and b==3)) and a>b):
print('A')
else:
print('B')