#include "bits/stdc++.h"
using namespace std;
using Graph = vector<vector<int>>;
typedef long long ll;
typedef pair<ll, ll> P;
#define rep(i,n) for (ll i = 0; i < (n); ++i)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
const long long mod = 1e9 + 7;

ll gcd(ll a, ll b) {
	return b ? gcd(b, a % b) : a;
}

ll lcm(ll a, ll b) {
	return a / gcd(a, b) * b;
}

int main() {
	ll a, b, c;
	cin >> a >> b >> c;

	vector<pair<ll, string>> vp;

	vp.push_back(make_pair(a, "A"));
	vp.push_back(make_pair(b, "B"));
	vp.push_back(make_pair(c, "C"));

	sort(rall(vp));

	for (auto p : vp) {
		cout << p.second << endl;
	}
}