#include <iostream>
#include <vector>
#include <algorithm> 
#include <queue>
#include <functional>
#include <map>
#include <string>
using namespace std;

typedef long long ll;



int main(void){

    int A, B, C, wa, wb, wc;
    cin >> A >> wa >> B >> wb >> C >> wc;
    int a[3] = { A, B, C };
    int w[3] = { wa, wb, wc };
    
    for (int i = 0; i < 3; i++){
        for (int j = 0; j < 2; j++){
            if (a[j + 1] <= a[j]){
                swap(a[j], a[j + 1]);

                
                if (a[j + 1] == a[j]){
                    if (w[j+1] < w[j]){
                        swap(a[j], a[j + 1]);
                        continue;
                    }
                }

                swap(w[j], w[j + 1]);
                
            }
        }
    }

    for (int i = 2; i >= 0; i--){
        if (a[i] == A&&w[i] == wa){
            cout << 'A' << endl;
        }
        else if (a[i] == B&&w[i]== wb){
            cout << 'B' << endl;
        }
        else if (a[i] == C&&w[i] == wc){
            cout << 'C' << endl;
        }
    }




}