#include <algorithm>
#include <array>
#include <bit>
#include <bitset>
#include <cassert>
#include <chrono>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <unordered_map>
#include <unordered_set>
#include <vector>
#define FOR(i, n, m) for (int i = n; i < (int)m; ++i)
#define REP(i, n) FOR (i, 0, n)
#define ALL(v) v.begin(), v.end()
#define PB push_back
using namespace std;
using ll = long long;
constexpr long long INF = 1000000000;
constexpr long long MOD = 998244353;
using P = pair<int, int>;

const std::string COLOR_RESET = "\033[0m", BRIGHT_GREEN = "\033[1;32m",
                  BRIGHT_RED = "\033[1;31m", BRIGHT_CYAN = "\033[1;36m",
                  NORMAL_CROSSED = "\033[0;9;37m",
                  RED_BACKGROUND = "\033[1;41m", NORMAL_FAINT = "\033[0;2m";

#ifdef RUN_LOCAL
#define dbg(x)                                                         \
    std::cerr << BRIGHT_CYAN << #x << COLOR_RESET << " = " << (x)      \
              << NORMAL_FAINT << " (L" << __LINE__ << ") " << __FILE__ \
              << COLOR_RESET << std::endl
#define dbgif(cond, x)                                                      \
    ((cond) ? std::cerr << BRIGHT_CYAN << #x << COLOR_RESET << " = " << (x) \
                        << NORMAL_FAINT << " (L" << __LINE__ << ") "        \
                        << __FILE__ << COLOR_RESET << std::endl             \
            : std::cerr)
#define msg(s)                                                          \
    std::cerr << BRIGHT_GREEN << s << NORMAL_FAINT << " (L" << __LINE__ \
              << ") " << __FILE__ << COLOR_RESET << std::endl
#else
#define dbg(x) 0
#define dbgif(cond, x) 0
#define msg(s) 0
#endif

template <typename T>
inline bool chmax(T &a, T b) {
    return a < b && (a = b, true);
}

template <typename T>
inline bool chmin(T &a, T b) {
    return a > b && (a = b, true);
}

template <class T1, class T2>
std::pair<T1, T2> operator+(const std::pair<T1, T2> &l,
                            const std::pair<T1, T2> &r) {
    return std::make_pair(l.first + r.first, l.second + r.second);
}
template <class T1, class T2>
std::pair<T1, T2> operator-(const std::pair<T1, T2> &l,
                            const std::pair<T1, T2> &r) {
    return std::make_pair(l.first - r.first, l.second - r.second);
}
template <class T>
std::vector<T> sort_unique(std::vector<T> vec) {
    sort(vec.begin(), vec.end()),
        vec.erase(unique(vec.begin(), vec.end()), vec.end());
    return vec;
}

template <class IStream, class T>
IStream &operator>>(IStream &is, std::vector<T> &vec) {
    for (auto &v : vec) is >> v;
    return is;
}

template <class OStream, class T>
OStream &operator<<(OStream &os, const std::vector<T> &vec);
template <class OStream, class T, size_t sz>
OStream &operator<<(OStream &os, const std::array<T, sz> &arr);
template <class OStream, class T, class TH>
OStream &operator<<(OStream &os, const std::unordered_set<T, TH> &vec);
template <class OStream, class T, class U>
OStream &operator<<(OStream &os, const std::pair<T, U> &pa);
template <class OStream, class T>
OStream &operator<<(OStream &os, const std::deque<T> &vec);
template <class OStream, class T>
OStream &operator<<(OStream &os, const std::set<T> &vec);
template <class OStream, class T>
OStream &operator<<(OStream &os, const std::multiset<T> &vec);
template <class OStream, class T>
OStream &operator<<(OStream &os, const std::unordered_multiset<T> &vec);
template <class OStream, class T, class U>
OStream &operator<<(OStream &os, const std::pair<T, U> &pa);
template <class OStream, class TK, class TV>
OStream &operator<<(OStream &os, const std::map<TK, TV> &mp);
template <class OStream, class TK, class TV, class TH>
OStream &operator<<(OStream &os, const std::unordered_map<TK, TV, TH> &mp);
template <class OStream, class... T>
OStream &operator<<(OStream &os, const std::tuple<T...> &tpl);

template <class OStream, class T>
OStream &operator<<(OStream &os, const std::vector<T> &vec) {
    os << '[';
    for (auto v : vec) os << v << ',';
    os << ']';
    return os;
}
template <class OStream, class T, size_t sz>
OStream &operator<<(OStream &os, const std::array<T, sz> &arr) {
    os << '[';
    for (auto v : arr) os << v << ',';
    os << ']';
    return os;
}
template <class... T>
std::istream &operator>>(std::istream &is, std::tuple<T...> &tpl) {
    std::apply([&is](auto &&...args) { ((is >> args), ...); }, tpl);
    return is;
}
template <class OStream, class... T>
OStream &operator<<(OStream &os, const std::tuple<T...> &tpl) {
    os << '(';
    std::apply([&os](auto &&...args) { ((os << args << ','), ...); }, tpl);
    return os << ')';
}
template <class OStream, class T, class TH>
OStream &operator<<(OStream &os, const std::unordered_set<T, TH> &vec) {
    os << '{';
    for (auto v : vec) os << v << ',';
    os << '}';
    return os;
}

template <class OStream, class T>
OStream &operator<<(OStream &os, const std::deque<T> &vec) {
    os << "deq[";
    for (auto v : vec) os << v << ',';
    os << ']';
    return os;
}
template <class OStream, class T>
OStream &operator<<(OStream &os, const std::set<T> &vec) {
    os << '{';
    for (auto v : vec) os << v << ',';
    os << '}';
    return os;
}
template <class OStream, class T>
OStream &operator<<(OStream &os, const std::multiset<T> &vec) {
    os << '{';
    for (auto v : vec) os << v << ',';
    os << '}';
    return os;
}
template <class OStream, class T>
OStream &operator<<(OStream &os, const std::unordered_multiset<T> &vec) {
    os << '{';
    for (auto v : vec) os << v << ',';
    os << '}';
    return os;
}
template <class OStream, class T, class U>
OStream &operator<<(OStream &os, const std::pair<T, U> &pa) {
    return os << '(' << pa.first << ',' << pa.second << ')';
}
template <class OStream, class TK, class TV>
OStream &operator<<(OStream &os, const std::map<TK, TV> &mp) {
    os << '{';
    for (auto v : mp) os << v.first << "=>" << v.second << ',';
    os << '}';
    return os;
}
template <class OStream, class TK, class TV, class TH>
OStream &operator<<(OStream &os, const std::unordered_map<TK, TV, TH> &mp) {
    os << '{';
    for (auto v : mp) os << v.first << "=>" << v.second << ',';
    os << '}';
    return os;
}

struct Watch {
    using Clock = std::chrono::high_resolution_clock;
    using TimePoint = std::chrono::time_point<Clock>;
    TimePoint start_time;
    std::chrono::duration<double> elapsed;
    bool running;
    Watch() : elapsed(0), running(false) {}
    void start() {
        if (!running) {
            start_time = Clock::now();
            running = true;
        }
    }
    void stop() {
        if (running) {
            elapsed += Clock::now() - start_time;
            running = false;
        }
    }
    double elapsed_seconds() const {
        if (running) {
            return elapsed.count() +
                   std::chrono::duration<double>(Clock::now() - start_time)
                       .count();
        } else {
            return elapsed.count();
        }
    }
    void reset() {
        running = false;
        elapsed = std::chrono::duration<double>::zero();
    }
};

struct modint {
    ll n;

   public:
    modint(const ll n = 0) : n((n % MOD + MOD) % MOD) {}
    static modint pow(modint a, int m) {
        modint r = 1;
        while (m > 0) {
            if (m & 1) {
                r *= a;
            }
            a = (a * a);
            m /= 2;
        }
        return r;
    }
    modint &operator++() {
        *this += 1;
        return *this;
    }
    modint &operator--() {
        *this -= 1;
        return *this;
    }
    modint operator++(int) {
        modint ret = *this;
        *this += 1;
        return ret;
    }
    modint operator--(int) {
        modint ret = *this;
        *this -= 1;
        return ret;
    }
    modint operator~() const { return (this->pow(n, MOD - 2)); }  // inverse
    friend bool operator==(const modint &lhs, const modint &rhs) {
        return lhs.n == rhs.n;
    }
    friend bool operator<(const modint &lhs, const modint &rhs) {
        return lhs.n < rhs.n;
    }
    friend bool operator>(const modint &lhs, const modint &rhs) {
        return lhs.n > rhs.n;
    }
    friend modint &operator+=(modint &lhs, const modint &rhs) {
        lhs.n += rhs.n;
        if (lhs.n >= MOD) lhs.n -= MOD;
        return lhs;
    }
    friend modint &operator-=(modint &lhs, const modint &rhs) {
        lhs.n -= rhs.n;
        if (lhs.n < 0) lhs.n += MOD;
        return lhs;
    }
    friend modint &operator*=(modint &lhs, const modint &rhs) {
        lhs.n = (lhs.n * rhs.n) % MOD;
        return lhs;
    }
    friend modint &operator/=(modint &lhs, const modint &rhs) {
        lhs.n = (lhs.n * (~rhs).n) % MOD;
        return lhs;
    }
    friend modint operator+(const modint &lhs, const modint &rhs) {
        return modint(lhs.n + rhs.n);
    }
    friend modint operator-(const modint &lhs, const modint &rhs) {
        return modint(lhs.n - rhs.n);
    }
    friend modint operator*(const modint &lhs, const modint &rhs) {
        return modint(lhs.n * rhs.n);
    }
    friend modint operator/(const modint &lhs, const modint &rhs) {
        return modint(lhs.n * (~rhs).n);
    }
};
istream &operator>>(istream &is, modint m) {
    is >> m.n;
    return is;
}
ostream &operator<<(ostream &os, modint m) {
    os << m.n;
    return os;
}

#define MAX_N 10000000
long long extgcd(long long a, long long b, long long &x, long long &y) {
    long long d = a;
    if (b != 0) {
        d = extgcd(b, a % b, y, x);
        y -= (a / b) * x;
    } else {
        x = 1;
        y = 0;
    }
    return d;
}

long long mod_inverse(long long a, long long m) {
    long long x, y;
    if (extgcd(a, m, x, y) == 1) return (m + x % m) % m;
    else return -1;
}

vector<long long> fact(MAX_N + 1, INF), fact_inv(MAX_N + 1, INF);
modint mod_comb(long long n, long long k) {
    if (n < 0 || k < 0 || n < k) return 0;
    if (fact[0] == INF) {
        fact[0] = 1;
        for (ll i = 1; i <= MAX_N; ++i) {
            fact[i] = (fact[i - 1] * i) % MOD;
        }
        fact_inv[MAX_N] = mod_inverse(fact[MAX_N], MOD);
        for (ll i = MAX_N - 1; i >= 0; i--) {
            fact_inv[i] = (fact_inv[i + 1] * (i + 1)) % MOD;
        }
    }
    return (((fact[n] * fact_inv[k]) % MOD) * fact_inv[n - k]) % MOD;
}

using mi = modint;

mi mod_pow(mi a, ll n) {
    mi ret = 1;
    mi tmp = a;
    while (n > 0) {
        if (n % 2) ret *= tmp;
        tmp = tmp * tmp;
        n /= 2;
    }
    return ret;
}

struct UnionFind {
    vector<int> data;
    vector<int> a;
    vector<int> b;

    UnionFind() = default;

    explicit UnionFind(size_t sz) : data(sz, -1), a(sz, 0), b(sz, 0) {}

    int unite(int x, int y) {
        x = find(x), y = find(y);
        if (x == y) return false;
        if (data[x] > data[y]) swap(x, y);
        data[x] += data[y];
        data[y] = x;
        a[x] += a[y];
        b[x] += b[y];
        int ret = min(a[x], b[x]);
        a[x] -= ret;
        b[x] -= ret;
        return ret;
    }

    int find(int k) {
        if (data[k] < 0) return (k);
        return data[k] = find(data[k]);
    }

    int size(int k) { return -data[find(k)]; }

    bool same(int x, int y) { return find(x) == find(y); }

    vector<vector<int>> groups() {
        int n = (int)data.size();
        vector<vector<int>> ret(n);
        for (int i = 0; i < n; ++i) {
            ret[find(i)].emplace_back(i);
        }
        ret.erase(remove_if(begin(ret), end(ret),
                            [&](const vector<int> &v) { return v.empty(); }),
                  end(ret));
        return ret;
    }
};

uint64_t xorshift(ll n = 0) {
    static uint64_t state[2] = {123456789ULL, 987654321ULL};

    uint64_t s1 = state[0];
    uint64_t s0 = state[1];
    state[0] = s0;
    s1 ^= s1 << 23;
    state[1] = s1 ^ s0 ^ (s1 >> 17) ^ (s0 >> 26);
    return (n != 0) ? ((state[1] + s0) % n) : (state[1] + s0);
}

template <typename T>
struct BinaryIndexedTree {
   private:
    int n;
    vector<T> data;

   public:
    BinaryIndexedTree() = default;

    explicit BinaryIndexedTree(int n) : n(n) { data.assign(n + 1, T()); }

    explicit BinaryIndexedTree(const vector<T> &v)
        : BinaryIndexedTree((int)v.size()) {
        build(v);
    }

    void build(const vector<T> &v) {
        assert(n == (int)v.size());
        for (int i = 1; i <= n; i++) data[i] = v[i - 1];
        for (int i = 1; i <= n; i++) {
            int j = i + (i & -i);
            if (j <= n) data[j] += data[i];
        }
    }

    void apply(int k, const T &x) {
        for (++k; k <= n; k += k & -k) data[k] += x;
    }

    T prod(int r) const {
        T ret = T();
        for (; r > 0; r -= r & -r) ret += data[r];
        return ret;
    }

    T prod(int l, int r) const { return prod(r) - prod(l); }

    int lower_bound(T x) const {
        int i = 0;
        for (int k = 1 << (__lg(n) + 1); k > 0; k >>= 1) {
            if (i + k <= n && data[i + k] < x) {
                x -= data[i + k];
                i += k;
            }
        }
        return i;
    }

    int upper_bound(T x) const {
        int i = 0;
        for (int k = 1 << (__lg(n) + 1); k > 0; k >>= 1) {
            if (i + k <= n && data[i + k] <= x) {
                x -= data[i + k];
                i += k;
            }
        }
        return i;
    }
};

void solve() {
    int n;
    cin >> n;
    vector<int> d(n);
    REP (i, n) cin >> d[i];
    sort(ALL(d));
    string ans = "";
    REP (i, n) ans += 'A' + (d[i] % 26);
    cout << ans << endl;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    int t = 1;
    // cin >> t;
    while (t--) {
        solve();
    }
}