#include<bits/stdc++.h>
typedef long long ll;
typedef unsigned long long ull;
using namespace std;
#define pb push_back
int dy[]={0, 0, 1, -1, 1, 1, -1, -1};
int dx[]={1, -1, 0, 0, 1, -1, -1, 1};

#define FOR(i,a,b) for (int i=(a);i<(b);i++)
#define RFOR(i,a,b) for (int i=(b)-1;i>=(a);i--)
#define REP(i,n) for (int i=0;i<(n);i++)
#define RREP(i,n) for (int i=(n)-1;i>=0;i--)
#define mp make_pair
#define fi first
#define sc second
pair<int,int> h[4];
int a[4];
int main(){
	cin >> a[0] >> a[1] >> a[2];

	REP(i,3){
		h[i] = mp(a[i],i);
	}
	sort(h,h+3);

	RREP(i,3){
		printf("%c\n",'A' + h[i].sc);
	}
	return 0;
}