#include <bits/stdc++.h>

using namespace std;

#define fst(t) std::get<0>(t)
#define snd(t) std::get<1>(t)
#define thd(t) std::get<2>(t)
#define unless(p) if(!(p))
#define until(p) while(!(p))

using ll = long long;
using P = std::tuple<int,int>;

const int dx[8] = {-1, 1, 0, 0, -1, -1, 1, 1}, dy[8] = {0, 0, -1, 1, -1, 1, -1, 1};

int main(){
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);

    int N;
    std::cin >> N;

    ll sum = 0ll;
    int C[200], two_n = 0, three_n = 0;
    for(int i=0;i<N;++i){
        std::cin >> C[i];
        sum += C[i];
        if(C[i] == 2){
            ++two_n;
        }else if(C[i] >= 3){
            ++three_n;
        }
    }

    if(sum % 2 == 0 || three_n >= 1 || two_n >= 2){
        std::cout << "B" << std::endl;
    }else{
        std::cout << "A" << std::endl;
    }
}