#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
using namespace std;
typedef long long int ll;
typedef pair<int,int> P;
#define yn {puts("A");}else{puts("B");}
#define MAX_N 200005

int main() {
    int n;
    cin >> n;
    ll c[n];
    ll sum = 0;
    ll cnt = 0;
    rep(i,n){
        cin >> c[i];
        sum += c[i];
        if(c[i] == 2)cnt++;
        if(c[i] >= 3)cnt += 2;
    }

    int flag = 1;
    if(sum % 2 == 0)flag = 0;
    if(cnt >= 2)flag = 0;
    
    if(flag)yn;
    return 0;
}