#include<bits/stdc++.h>
typedef long long ll;
using namespace std;
int INF = 1LL << 30;
int MOD = 1e9+7;
main(){
    vector<pair<int,char> > v;
    for(int i = 0;i < 3;i++){
        int a;
        cin >> a;
        v[i] = make_pair(a,'A' + i);
    }
    sort(v.rbegin(),v.rend());
    for(auto p:v){
        cout << p.second << endl;
    }
}