#include <iostream>
#include <vector>
#include <list>
#include <algorithm>
#include <string>
#include <sstream>
#include <stack>
#include <iomanip>
#include <numeric>
#include <queue>
#include <climits>
#include <set>
#include <complex>
#include <cmath>
#include <cstring>
#include <map>
using namespace std;
using ll = long long;
#define MOD 1000000007
#define INF 1LL << 59
using ld = long double;

bool operator<(const pair<int, int> &a, const pair<int, int> &b)
{
    if (a.first == b.first)
    {
        return b.second > a.second;
    }
    return a.first < b.first;
}

vector<int> v;
vector<vector<int>> v2(2010);
int main()
{
    std::ios::sync_with_stdio(false);
    std::cin.tie(0);
    //cout << fixed << setprecision(6);

    int Ha, Wb, Hb, Wa, Hc, Wc;
    cin >> Ha >> Wa >> Hb >> Wb >> Hc >> Wc;
    vector<pair<int, int>> vp;
    vp.push_back({Ha, -Wa});
    vp.push_back({Hb, -Wb});
    vp.push_back({Hc, -Wc});

    sort(vp.rbegin(), vp.rend());

    for (int i = 0; i < 3; ++i)
    {
        if (vp[i].first == Ha && vp[i].second == -Wa)
            cout << "A" << endl;
        else if (vp[i].first == Hb && vp[i].second == -Wb)
        {
            cout << "B" << endl;
        }
        else
        {
            cout << "C" << endl;
        }
    }

    return 0;
}