#include <bits/stdc++.h>
using namespace std;

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int N; cin >> N;
    vector<int> D(N);
    for(auto &d : D) cin >> d;
    sort(D.begin(),D.end());
    for(auto d : D) cout << char('A'+d%26); cout << endl;
}