1 #include <iostream>
 2 #include <cmath>
 3 using namespace std;
 4 int main(){
 5     int a, b;
 6     while(cin >> a >> b){
 7         if(a < b) swap(a, b);
 8         int cmp = (a - b) * (1 + sqrt(5) / 2);
 9         if(cmp == a){
10             cout << ‘A‘ << endl;
11         }
12         else cout << ‘B‘ << endl;
13     }
14 }