#include<iostream>
#include<cstdio>
#include<cstring>
#include <cstdlib>  
#include <cmath>   
#include<cctype>
#include<string>
#include<set>
#include<iomanip>
#include <map>
#include<algorithm>
#include <functional>
#include<vector>
#include<climits>
#include<stack>
#include<queue>
#include <deque>
#include <climits>
#include <typeinfo>
#include <utility> 
#define all(x) (x).begin(),(x).end()
#define rep(i,m,n) for(int i = m;i < n;++i)
#define pb push_back
#define fore(i,a) for(auto &i:a)
#define rrep(i,m,n) for(int i = m;i >= n;--i)
#define INF INT_MAX/2
using namespace std;
using ll = unsigned long long int;
using R = double;
using Data = pair<ll, vector<int>>;
const ll MOD = 1e9 + 7;
const ll inf = 1LL << 50;
struct edge { ll from; ll to; ll cost; };

int main() {
	int n;
	cin >> n;

	int check = 0;
	int cnt1 = 0;
	int cnt2 = 0;
	int cnt0 = 0;
	rep(i, 0, n) {
		int c;
		cin >> c;
		check += c % 2;
		if (c == 1)cnt1++;
		else if (c == 2)cnt2++;
		else if(c == 0)cnt0++;
	}

	if (check % 2 == 0) {
		cout << "B" << endl;
	}else{
		if ((cnt1 == n-cnt0 - 1 && cnt2 == 1) || cnt1 == n-cnt0) {
			cout << "A" << endl;
		}
		else {
			cout << "B" << endl;
		}
	}



	return 0;
}