/**
 * @(#)iProfits.java
 *
 *
 * @author 
 * @version 1.00 2009/10/21
 */

import java.io.*;
import java.lang.*;
import java.util.*;

public class S4 {

	public static void main(String args[]) throws Exception {
		BufferedReader in = new BufferedReader(new FileReader("DATA4.txt"));
		PrintWriter outputStream = new PrintWriter(new BufferedWriter(new FileWriter("OUT4.txt")));
		for (int x=0; x < 5; x++) {
			String[][] cha = new String[2][90];
			String a = in.readLine();
			String b = in.readLine();
			
			for (int y = 0; y < a.length(); y++) {
				cha[0][y] = a.substring(y, y + 1);
			}
			
			cha[0][a.length()] = " ";
			cha[0][a.length() + 1] = " ";
			cha[0][a.length() + 2] = " ";
			cha[0][a.length() + 3] = " ";
			
			for (int y = 0; y < b.length(); y++) {
				cha[1][y] = b.substring(y, y + 1);
			}
			
			cha[1][a.length() ] = " ";
			cha[1][a.length() + 1] = " ";
			cha[1][a.length() + 2] = " ";
			cha[1][a.length() + 3] = " ";
			
			for (int i = 0; i < a.length(); i++) {
				if (cha[1][i].compareTo(".") == 0) {
					if (cha[1][i + 2].compareTo("x") == 0 && cha[0][i + 2].compareTo("x") == 0) {
						if (cha[0][i + 3].compareTo("x") == 0 && cha[1][i + 3].compareTo("x") == 0) {
							outputStream.print("E");
							i += 2;
							continue;
						} else {	
							outputStream.print("D");
							i += 1;
							continue;
						}
					}
				} else {
					if (cha[1][i + 1].compareTo("x") == 0 && cha[0][i + 1].compareTo(".") == 0){
						if (cha[1][i + 2].compareTo("x") == 0 && cha[0][i + 2].compareTo("x") == 0) {
							if (cha[0][i + 3].compareTo("x") == 0 && cha[1][i + 3].compareTo("x") == 0) {
								outputStream.print("C");
								i += 2;
								continue;
							} else {	
								outputStream.print("A");
								i += 1;
								continue;
							}
						}
					}else 
						outputStream.print("B");
						i += 1;	
						continue;
				}
			}
			outputStream.println("");
		}
		outputStream.close();
		System.exit(0);
	}
}