0b7e0e9734c5593ba3da2cf7625b70389ae1094b6544c5b25ff1f54eadbd4dfe
// https://szkopul.edu.pl/problemset/problem/xCD6DZuiNwxyySDwBY_Yx3rV/site/?key=statement
#include <iostream>
#include <vector>
int main() {
std::ios_base::sync_with_stdio(0);
std::cin.tie(0);
std::cout.tie(0);
int n;
std::cin >> n;
std::vector<int> v(n);
int local_maxi = 0;
for (int i = 0; i < n; i++) {
std::cin >> v[i];
local_maxi = std::max(local_maxi, v[i]);
}
std::string ans;
for (int i = 0; i < n; i++) {
if (v[i] == local_maxi) {
ans += (char)('A' + i);
}
}
std::cout << ans << '\n';
return 0;
}