#include <iostream>
#include <stdio.h>
#include <algorithm>
#include <math.h>
#include <utility>
#include <vector>
using namespace std;


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

    p[0].second = 'A';
    p[1].second = 'B';
    p[2].second = 'C';

    cin >> p[0].first >> p[1].first >> p[2].first;

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

    for(int i=0; i<3; i++)
        cout << p[2-i].second << endl;

    return 0;
}