#include <iostream>
#include <algorithm>
#include <vector>

void solve() {
    std::vector<std::pair<int, char>> hs(3);
    for (int i = 0; i < 3; ++i) {
        std::cin >> hs[i].first;
        hs[i].second = 'A' + i;
    }

    std::sort(hs.rbegin(), hs.rend());
    for (auto p : hs) std::cout << p.second << std::endl;
}

int main() {
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);

    solve();

    return 0;
}