#include<iostream>
#include<string>
#include<algorithm>
#include<cctype>
#include<set>
#include<bitset>
#include<math.h>
#include<map>
#include<queue>
#include<iomanip>
using namespace std;

int main(){
    vector<pair<int, string>> v(3);
    for (int i = 0; i < 3; i++){
        cin >> v[i].first;
        v[i].second = 'A' + i;
    }
    sort(v.begin(), v.end(), greater());
    for (auto x : v) cout << x.second << endl;
}