#include <bits/stdc++.h>
//#include <atcoder/all>
using namespace std;
//using namespace atcoder;
typedef long long ll;
typedef pair<ll,ll> P;
//typedef modint998244353 mint;
#define rep(i,a,b) for(int i=a;i<b;i++)
#define rrep(i,a,b) for(int i=a;i>=b;i--)
ll n;
ll c[200];
ll o,t,m;
int main(void){
    cin.tie(0);
    ios::sync_with_stdio(0);
    cin>>n;
    rep(i,0,n){
        cin>>c[i];
        if(c[i]==1){
            o++;
        }else if(c[i]==2){
            t++;
        }else if(c[i]>2){
            m++;
        }
    }
    if((o%2==1&&m==0)||(o%2==1&&t==1&&m==0)){
        cout<<"A"<<endl;
    }else{
        cout<<"B"<<endl;
    }

}