import java.util.*;

public class Main {
    public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
    int [] h = new int [3];
    HashMap <Integer, String> map = new HashMap<>();
    for (int i = 0; i < 3; i++) {
      h[i] = sc.nextInt();
    }
      map.put (h[0], "A");
      map.put (h[1], "B");
      map.put (h[2], "C");
      Arrays.sort(h);

      for (int i = 0; i < 3; i++) {
        System.out.println(map.get(h[2-i]));
      }
      sc.close();
    }
  }