#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

int main(void) {
    ll A,B,C;
    vector< pair<int, char> > tall;
    cin >> A >> B >> C;
    tall.push_back(make_pair(A,'A'));
    tall.push_back(make_pair(B,'B'));
    tall.push_back(make_pair(C,'C'));
    sort(tall.begin(), tall.end());
    reverse(tall.begin(), tall.end());
    for (auto x:tall) {
        cout << x.second << endl;
    }
    return 0;
}