#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(n);++i)
#define all(a) (a).begin(),(a).end()
#define dunk(a) cout << (a) << endl
using namespace std;
typedef long long ll;

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	string s = "ABC";

	vector<pair<pair<int, int>, char>> ans;

	rep(i, 3) {
		int a, b; cin >> a >> b;
		ans.push_back({ {a,b},s[i] });
	}

	sort(all(ans), [&](pair<pair<int, int>, char> a, pair<pair<int, int>, char> b) {
		if (a.first.first != b.first.first) return a.first.first > b.first.first;
		return a.first.second < b.first.second;

	});

	rep(i, 3) {
		dunk(ans[i].second);
	}

	return 0;
}