#include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < n; ++i)
using ll = long long;
using namespace std;
const int INF = 1e9;

int main() {
    vector<pair<int, char>> h(3);
    rep(i, 3) {
        cin >> h[i].first;
        h[i].second = char('A' + i);
    }

    sort(h.rbegin(), h.rend());
    rep(i, 3) cout << h[i].second << endl;

    return 0;
}