#include <bits/stdc++.h>

using namespace std;

int main() {
    vector<pair<int, int>> vt;
    for (int i = 0; i < 3; ++i) {
        int h;
        cin >> h;
        vt.emplace_back(h, i);
    }

    sort(vt.begin(), vt.end(), greater<>());
    for (int i = 0; i < 3; ++i) {
        cout << (char) ('A' + vt[i].second) << endl;
    }
    return 0;
}