package m.shin;
import java.util.Scanner;
//未完成
import java.util.TreeMap;
public class Sankyodai {

	public static void main(String[] args) {
		Scanner s = new Scanner(System.in);
		int[] t = new int[3];
		TreeMap<Integer,String> brother = new TreeMap<>();
		t[0] = s.nextInt();
		brother.put(t[0], "A");
		t[1] = s.nextInt();
		brother.put(t[1], "B");
		t[2] = s.nextInt();
		brother.put(t[2], "C");

		for(int i = 0;i < 2;i++){
			for(int k = 0;k < 2;k++){
				if(t[k] < t[k+1]){
					int r = t[k];
					t[k] = t[k+1];
					t[k+1] = r;
				}
			}
		}
		for(int i = 0;i < 3;i++){
			System.out.println(brother.get(t[i]));
		}
		s.close();

	}

}