#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <stack>
#include <algorithm>
#include <string>
#include <map>
#include <iterator>
#include <set>
#include <queue>

using namespace std;


int main() {

    vector<char> vs = {'A', 'B', 'C'};
    vector<pair<int, char>> as;
    for (int i = 0; i < 3; ++i) {
        int H;
        cin >> H;
        as.emplace_back(H, vs[i]);
    }

    sort(as.begin(), as.end(), greater<pair<int, char>>());

    for (int i = 0; i < 3; ++i) {
        cout << as[i].second << endl;
    }

    return 0;
}