#include <bits/stdc++.h>
#define FOR(i,a,b) for(int i = (a); i < (b); ++i)
#define REP(i,n) FOR(i,0,n)
#define SZ(n) (int)(n).size()
#define ALL(n) (n).begin(), (n).end()
#define MOD % 1000000007
using namespace std;
typedef long long LL;
typedef vector<int> VI;
typedef pair<int, int> PI;


int main() {
	pair<pair<int, int>, char> p[3];
	REP(i, 3) {
		cin >> p[i].first.first >> p[i].first.second;
		p[i].second = 'A' + i;
	}
	sort(p, p + 3, greater<pair<pair<int, int>, char>>());
	REP(i, 2) {
		FOR(j, i + 1, 3) {
			if (p[i].first.first == p[j].first.first && p[i].first.second > p[j].first.second) swap(p[i], p[j]);
		}
	}
	REP(i, 3) {
		cout << p[i].second << endl;
	}
	return 0;
}