#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
#include <map>

using namespace std;

int main()
{
    vector<pair<int, int> > p(3);

    for (int i=0; i<3; i++) {
        int a;  cin >> a;
        p[i] = make_pair(a, i);
    }

    sort(p.begin(), p.end());
    reverse(p.begin(), p.end());

    for (int i=0; i<3; i++) {
        char c = p[i].second + 'A';
        cout << c << endl;
    }

    return 0;
}