#include<iostream>
#include<string>
#include<cstring>
#include<complex>
#include<vector>
#include<algorithm>
using namespace std;

#define REP(i, j) for (int i = 0; i < (int)j; ++i)
#define FOR(i, j, k) for (int i = (int)j; i < (int)k; ++i)
#define SORT(v) sort(v.begin(), v.end())
#define REVERSE(v) reverse(v.begin(), v.end())
typedef complex<double> P;
typedef vector<int> VI;
typedef pair<int, char> PIC;
typedef long long LL;

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

	vector<PIC> hs;
	int a, b, c;
	cin >> a >> b >> c;
	hs.push_back(make_pair(a, 'A'));
	hs.push_back(make_pair(b, 'B'));
	hs.push_back(make_pair(c, 'C'));

	sort(hs.begin(), hs.end(), greater<PIC>());
	REP(i,3) {
		cout << hs[i].second << endl;
	}

	return 0;
}