#include <bits/stdc++.h>
#define int long long 
using namespace std;

signed main() {
vector<pair<int, char>> H(3);

string abc = "ABC";
int A;
for( int i = 0; i < 3; i++ ){
cin >> A;
H.at(i) = make_pair(A, abc.at(i));
}
sort(H.rbegin(), H.rend());

for( int i = 0; i < 3; i++ ) cout << H.at(i).second << endl;

}