#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef pair<ll,ll> P;
#define REP(i,n) for(ll i=0;i<ll(n);i++)







int main(void){
	cin.tie(nullptr);  ios_base::sync_with_stdio(false);
	ll i,j;




	ll N;
	cin >> N;

	vector<ll> d(N);
	REP(i,N) cin >> d[i];


	sort(d.begin(),d.end());

	REP(i,N){
		ll n=d[i]%26;
		cout << char('A'+n);
	}


	cout << endl;







	return 0;

}