#include "bits/stdc++.h"

#ifdef WINT_MIN
#define __MAI
#endif

using namespace std;
typedef unsigned int uint;
typedef long long int ll;
typedef unsigned long long int ull;

#define debugv(v) printf("L%d %s => ",__LINE__,#v);for(auto e:v){cout<<e<<" ";}cout<<endl;
#define debugm(m) printf("L%d %s is..\n",__LINE__,#m);for(auto v:m){for(auto e:v){cout<<e<<" ";}cout<<endl;}
#define debuga(m,w) printf("L%d %s is => ",__LINE__,#m);for(int x=0;x<(w);x++){cout<<(m)[x]<<" ";}cout<<endl;
#define debugaa(m,w,h) printf("L%d %s is..\n",__LINE__,#m);for(int y=0;y<(h);y++){for(int x=0;x<(w);x++){cout<<(m)[x][y]<<" ";}cout<<endl;}
#define debugaar(m,w,h) printf("L%d %s is..\n",__LINE__,#m);for(int y=0;y<(h);y++){for(int x=0;x<(w);x++){cout<<(m)[y][x]<<" ";}cout<<endl;}
#define ALL(v) (v).begin(),(v).end()
#define repeat(l) for(auto cnt=0;cnt<(l);++cnt)
#define BIGINT 0x7FFFFFFF
#define E107 1000000007ll
void printbit(int u) { if (u == 0)cout << 0; else { int s = 0, k = 0; for (; 0<u; u >>= 1, k++)s = (s << 1) | (u & 1); for (; 0<k--; s >>= 1)cout << (s & 1); } }template<typename T1, typename T2>
    ostream& operator <<(ostream &o, const pair<T1, T2> p) { o << "(" << p.first << ":" << p.second << ")"; return o; }

#define TIME chrono::system_clock::now()
#define MILLISEC(t) (chrono::duration_cast<chrono::milliseconds>(t).count())

namespace {
    std::chrono::system_clock::time_point t;
    void tic() { t = TIME; }
    void toc() { fprintf(stderr, "TIME : %lldms\n", MILLISEC(TIME - t)); }
    std::chrono::system_clock::time_point tle = TIME;
#ifdef __MAI
    void safe_tle(int msec) { assert(MILLISEC(TIME - tle) < msec); }
#else
#define safe_tle(k) ;
#endif
}

#ifndef __MAI 
namespace {
    class MaiScanner {
    public:
        template<typename T>
        void input_integer(T& var) {
            var = 0;
            T sign = 1;
            int cc = getchar_unlocked();
            for (; cc<'0' || '9'<cc; cc = getchar_unlocked())
                if (cc == '-') sign = -1;
            for (; '0' <= cc&&cc <= '9'; cc = getchar_unlocked())
                var = (var << 3) + (var << 1) + cc - '0';
            var = var*sign;
        }
        void ign() { getchar_unlocked(); }
        MaiScanner& operator>>(int& var) {
            input_integer<int>(var);
            return *this;
        }
        MaiScanner& operator>>(long long& var) {
            input_integer<long long>(var);
            return *this;
        }
    };
}
MaiScanner scanner;
#else
#define scanner cin
#endif
// ----------------------------------------------
// 個人的な便利ツールここまで
// ----------------------------------------------

inline int compare(int l, int r) { return l > r; }

#define A_SAN 1
#define B_SAN 0

int n;


// 実装内容の説明は #165951 を確認してください．

map<vector<char>, int> dp;
int solve(vector<char> cc) {

    sort(cc.begin(), cc.end() - 1, compare);

    auto dp_ref = dp.find(cc);
    if (dp_ref != dp.end()) return dp_ref->second;

    int turn = cc[n];

    cc[n] = !turn;
    for (int i = 0; i < n - 1 && cc[i] ; ++i) {
        --cc[i];
        if (solve(cc) == turn) {
            ++cc[i]; cc[n] = turn;
            return dp[cc] = turn;
        }

        if (turn == B_SAN && cc[i]) {
            --cc[i];
            if (solve(cc) == turn) {
                cc[i] += 2; cc[n] = turn;
                return dp[cc] = turn;
            }
            ++cc[i];
        }
        ++cc[i];
    }

    cc[n] = turn;
    return dp[cc] = !turn;
}




int main() {
    int a;
    scanner >> n;

    vector<char> cc(n + 1);

    repeat(n) {
        scanner >> a;
        cc[cnt] = min(3, a);
    }

    sort(ALL(cc), compare);

    cc[n] = A_SAN;

    cout << (solve(cc) ? "A" : "B") << endl;

    return 0;
}