#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i, n) for(int i = 0; i < (n); i++)
#define rep1(i, n) for(int i = 1; i <= (n); i++)
#define co(x) cout << (x) << "\n"
#define cosp(x) cout << (x) << " "
#define ce(x) cerr << (x) << "\n"
#define cesp(x) cerr << (x) << " "
#define pb push_back
#define mp make_pair
#define Would
#define you
#define please

int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);


	pair<int, char> H[3];
	int h;
	cin >> h;
	H[0] = mp(-h, 'A');
	cin >> h;
	H[1] = mp(-h, 'B');
	cin >> h;
	H[2] = mp(-h, 'C');
	sort(H, H + 3);
	rep(i, 3) co(H[i].second);


	Would you please return 0;
}