#include <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()
#define fi first
#define se second
template<typename A, typename B> inline bool chmax(A &a, B b) { if (a<b) { a=b; return 1; } return 0; }
template<typename A, typename B> inline bool chmin(A &a, B b) { if (a>b) { a=b; return 1; } return 0; }
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<pll, int> plp;
const ll INF = 1e9+100;
const ll MOD = 1e9+7;
const double EPS = 1e-10;
const bool debug = 0;
//--------------------------------//

int n;
int c[150];

int main() {
	cin >> n;
	REP(i, n) cin >> c[i];
	
	bool ans = false;
	int cnt = 0, one = 0, two = 0;
	REP(i, n) {
		if (c[i] >= 3) ans = true;
		if (c[i] == 2) two++;
		if (c[i] == 1) one++;
	}
	
	if (two >= 2) ans = true;
	if (!ans && one % 2 == 0) ans = true;
	
	puts(ans ? "B" : "A");
	
	return 0;
}