2490.cpp

// Authored by : wogha95
// Co-authored by : BaaaaaaaaaaarkingDog
// http://boj.kr/38cf0450b8c8458e859c486e3ea80323
#include <bits/stdc++.h>
using namespace std;

int result, input;
string res = "DCBAE";

int main(void){
  ios::sync_with_stdio(0);
  cin.tie(0);
    
  for(int r = 0; r < 3; r++) {
    result = 0;
    for(int c = 0; c < 4; c++) {
      cin >> input;
      result += input;
    }
    cout << res[result] << '\n';
  }
}