#include <iostream>
#include <map>
using namespace std;

int main() {
    map<int, char> mp;
    int a, b, c;
    cin >> a >> b >> c;
    mp[a] = 'A';
    mp[b] = 'B';
    mp[c] = 'C';
    for (auto itr = mp.rbegin(); itr != mp.rend(); itr++) {
        cout << itr->second << endl;
    }
    return 0;
}