// #define _GLIBCXX_DEBUG // for STL debug (optional)
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <string>
#include <cstring>
#include <deque>
#include <list>
#include <queue>
#include <stack>
#include <vector>
#include <utility>
#include <algorithm>
#include <map>
#include <set>
#include <complex>
#include <cmath>
#include <limits>
#include <cfloat>
#include <climits>
#include <ctime>
#include <cassert>
#include <numeric>
#include <fstream>
#include <functional>
#include <bitset>
using namespace std;

#define debug(...) fprintf(stderr, __VA_ARGS__)
#define int long long int
 
template<typename T> void chmax(T &a, T b) {a = max(a, b);}
template<typename T> void chmin(T &a, T b) {a = min(a, b);}
template<typename T> void chadd(T &a, T b) {a = a + b;}
 
typedef pair<int, int> pii;
typedef long long ll;
 
int dx[] = {0, 0, 1, -1};
int dy[] = {1, -1, 0, 0};
const ll INF = 1001001001001001LL;
const ll MOD = 1000000007LL;

const int S = 7;
int rec[S+5][S+5][S+5][S+5][S+5][S+5][S+5][3];

int solve(int a, int b, int c, int d, int e, int f, int g, int turn) {
    int &val = rec[a][b][c][d][e][f][g][turn];
    if(val >= 0) return val;

    val = 0;
    int n_turn = 3 - turn;
    for(int i=1; i<=turn; i++) {
        if(i <= a) val |= !solve(a-i, b  , c  , d  , e  , f  , g  , n_turn);
        if(i <= b) val |= !solve(a  , b-i, c  , d  , e  , f  , g  , n_turn);
        if(i <= c) val |= !solve(a  , b  , c-i, d  , e  , f  , g  , n_turn);
        if(i <= d) val |= !solve(a  , b  , c  , d-i, e  , f  , g  , n_turn);
        if(i <= e) val |= !solve(a  , b  , c  , d  , e-i, f  , g  , n_turn);
        if(i <= f) val |= !solve(a  , b  , c  , d  , e  , f-i, g  , n_turn);
        if(i <= g) val |= !solve(a  , b  , c  , d  , e  , f  , g-i, n_turn);
    }
    return val;
}

void test() {
    fill(rec[0][0][0][0][0][0][0], rec[S+1][0][0][0][0][0][0], -1);
    for(int i=0; i<=S; i++) {
        for(int j=i; j<=S; j++) {
            for(int k=j; k<=S; k++) {
                for(int l=k; l<=S; l++) {
                    for(int m=l; m<=S; m++) {
                        for(int n=m; n<=S; n++) {
                            for(int o=n; o<=S; o++) {
                                // 先手が勝ち
                                if(solve(i, j, k, l, m, n, o, 1) == 1) {
                                    fprintf(stderr, "winner is A: %lld, %lld, %lld, %lld, %lld, %lld, %lld\n", i, j, k, l, m, n, o);
                                }
                            }
                        }
                    }
                }
            }
        }
    }
}

signed main() {
    // test();
    
    int N; cin >> N;

    int cnt1 = 0, cnt2 = 0, cntF = 0;
    for(int i=0; i<N; i++) {
        int C; cin >> C;
        if(C == 1) cnt1++;
        else if(C == 2) cnt2++;
        else if(C  > 0) cntF++;
    }
    bool ok = true;
    ok &= (cnt1 % 2 == 1);
    ok &= (cnt2 <= 1);
    ok &= (cntF == 0);
    cout << (ok ? "A" : "B") << endl;
    return 0;
}