package yukicoder;

import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;

public class No574 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        HashMap<Character, Integer[]> map = new HashMap<>();

        for(int i = 0; i < 3; i++) {
            map.put((char)(65 + i), new Integer[]{sc.nextInt(), sc.nextInt()});
        }

        map.entrySet().stream().sorted(
                Map.Entry.comparingByValue((hu1, hu2) -> {
                    if(hu1[0] < hu2[0] || hu1[0] == hu2[0] && hu1[1] < hu2[1]) {
                        return 1;
                    } else {
                        return -1;
                    }
                })).forEach(m -> System.out.println(m.getKey()));
    }
}