#include <bits/stdc++.h>
#define rep(i,n)for(int i=0;i<(n);i++)
#define INF 0x3f3f3f3f
#define INFL 0x3f3f3f3f3f3f3f3f
#define EPS (1e-10)
#define MOD 1000000007
using namespace std;
typedef long long ll;
typedef pair<int,int>P;

signed main(){
	vector<P>v;
	rep(i,3){
		int a;cin>>a;
		v.push_back(P(a,i));
	}
	sort(v.begin(),v.end(),greater<>());
	for(auto p:v)printf("%c\n",p.second+'A');
}