#include <bits/stdc++.h>

using namespace std;

int main() {
    int N;
    cin >> N;
    vector<pair<int, int>> A(N);
    for (int i = 0; i < N; i++) {
        int a;
        cin >> a;
        A[i].first = a / 26;
        A[i].second = a % 26;
    }
    sort(A.begin(), A.end());
    for (int i = 0; i < N; i++) {
        cout << (char) ('A' + A[i].second);
    }
    cout << endl;
    return 0;
}