#include<iostream>
#include<vector>
#include<map>
#include<tuple>
#include<string>
#include<cmath>
#include<climits>
#include<algorithm>
#include<bitset>
#include<set>
 
using namespace std;  
typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vvi;
#define rep(i,n) for(ll i=0;i<(n);i++)  
#define pii pair<int,int>
#define piii pair<int,pii>
#define mp make_pair
#define pb push_back  
#define ALL(a) (a).begin(),(a).end()
#define FST first
#define SEC second  
const int INF = (INT_MAX/2);
const ll LLINF = (LLONG_MAX/2);
const double eps = 1e-5;
const double PI = M_PI;  
#define DEB cerr<<"!"<<endl
#define SHOW(a,b) cerr<<(a)<<" "<<(b)<<endl
#define SHOWARRAY(ar,i,j) REP(a,i)REP(b,j)cerr<<ar[a][b]<<((b==j-1)?((a==i-1)?("\n\n"):("\n")):(" "))
#define DIV 1000000007
ll pow(ll x,ll n,ll m){ll r=1;while(n>0){if(n&1==1)r=r*x%m;x=x*x%m;n>>=1;}return r%m;}
using namespace std;
  
int main(){
  cin.tie(0);ios_base::sync_with_stdio(0);
  typedef tuple<int,int,char> tiic;
  vector<tiic> vt(3);
  
  rep(i,3){
    int h,w; cin >> h >> w;
    vt[i] = tiic{h,w,'A'+i};
  }
  sort(ALL(vt),[](tiic a,tiic b){
    int h,hh,w,ww;
    char c,cc;
    tie(h,w,c) = a;
    tie(hh,ww,cc) = b;
    if(h != hh)
      return h > hh;
    else
      return w < ww;
  });
  
  rep(i,3){
    cout << get<2>(vt[i]) << endl;
  }
  
  return 0;
}