package yukicoder174;

import java.util.Arrays;
import java.util.Comparator;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt();
		int b = sc.nextInt();
		int c = sc.nextInt();
		Pair[] p = {new Pair(a, 'A'), new Pair(b, 'B'), new Pair(c, 'C')};
		Arrays.sort(p, new Comparator<Pair>() {
			public int compare(Pair p1, Pair p2) {
				return Integer.compare(p2.a, p1.a);
			}
		});
		for(int i = 0 ; i < 3 ; i++) {
			System.out.println(p[i].c);
		}
	}

	public static class Pair {
		int a; char c;
		public Pair(int a, char c) {
			this.a = a; this.c = c;
		}
	}

}