// #define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); ++i)
int main() {
    // Input
    int HA, HB, HC;
    cin >> HA >> HB >> HC;

    // Sort
    vector<char> bro = {'A', 'B', 'C'};
    vector<int> height = {HA, HB, HC};
    sort(bro.begin(), bro.end(), [&](char c1, char c2) {
        return height[c1 - 'A'] > height[c2 - 'A'];
    });

    // Output
    for (const char& person : bro) cout << person << endl;
}