#include <bits/stdc++.h>
#define REP(i,n,N) for(int i=(n);i<(int) N;i++)
#define RREP(i,n,N) for(int i=N-1;i>=(int) n;i--)
#define p(s) cout<<(s)<<endl
#define DEBUG(x,y) cout<<#x<<": "<<x<<" , "<<#y<<": "<<y<<endl;
#define CK(n,a,b) ((a)<=(n)&&(n)<=(b))
#define F first
#define S second
typedef long long ll;
using namespace std;
const int inf=1e9+7;

pair<int,char> A[3];
int main(){
	REP(i,0,3) {
		int a;
		cin>>a;
		A[i]={a,'A'+i};
	}
	sort(A,A+3);
	reverse(A,A+3);
	REP(i,0,3) p(A[i].S);
	return 0;
}