#include <bits/stdc++.h>

using namespace std;

typedef pair<int, int> pii;
typedef long long ll;
const int N = 2000086, MOD = 998244353, INF = 0x3f3f3f3f;
ll res;
int n, m, cnt, w[N];



int main() {
    cin >> n;
    for (int i = 1; i < n + 1; i++) scanf("%d", w + i);
    sort(w + 1, w + n + 1);
    for (int i = 1; i < n + 1; i++) {
        w[i] %= 26;
    }
    for (int i = 1; i < n + 1; i++) putchar(w[i] + 'A');
    return 0;
}