import java.util.*;

class Main {
	static Scanner sc = new Scanner(System.in);
	public static void main(String[] args) {
		
		Human[] brother = new Human[3];
		for (int i=0; i<3; i++) {
			brother[i] = new Human(String.valueOf((char)(i+65)), sc.nextInt());
		}
		Arrays.sort(brother, Comparator.comparing(Human::getHeight).reversed());
		
		for (int i=0; i<3; i++) {
			System.out.println(brother[i].name);
		}
		
	}
}

class Human {
	String name;
	int height;
	Human(String s, int n) {
		name = s;
		height = n;
	}
	int getHeight() {return height;}
}