#include <iostream>
#include <vector>
#include <algorithm> 
#include <queue>
#include <functional>
#include <map>
#include <string>
using namespace std;
typedef long long ll;


int main(void){
    vector<pair<int,char>> v(3);
    string s = "ABC";
    for (int i = 0; i < 3; i++){
        int x;
        cin >> x;
        v.push_back({ x, s[i] });
    }

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

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

}