#include <bits/stdc++.h>

using namespace std;

using ll = long long;
using P = pair<int, int>;

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    vector<P> v;
    vector<int> w = {0,1,2};
    for (int i = 0; i < 3; i++) {
        int h, w;
        cin >> h >> w;
        v.emplace_back(-h, w);
    }
    sort(w.begin(), w.end(), [&](const int& i1, const int& i2){return v[i1] < v[i2];});
    string s = "ABC";
    for (int i = 0; i < 3; i++) {
        cout << s[w[i]] << endl;
    }
    return 0;
}