import java.util.Scanner;
public class Main{
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
while(scan.hasNextLine()) {
String str = scan.nextLine();
int aNum = str.replace("B", "").length() - 1;//将B去掉,再把结尾“0”去掉,可得到A的数
int bNum = str.replace("A", "").length() - 1;//
if(aNum > bNum) {
System.out.println('A');
} else if(aNum < bNum) {
System.out.println('B');
} else {
System.out.println('E');
}
}
}
}