import java.util.Comparator;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Scanner;

public class No570 {

    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        LinkedHashMap<String, Integer> map = new LinkedHashMap<>();
        map.put("A", s.nextInt());
        map.put("B", s.nextInt());
        map.put("C", s.nextInt());
        map.entrySet().stream()
            .sorted(Map.Entry.comparingByValue(Comparator.reverseOrder()))
            .forEach(e -> System.out.println(e.getKey()));
    }
}