#include<stdio.h>
#include<string.h>
int main() {
    char ch[100] = {0};
    int i = 0, sum1 = 0, sum2 = 0;
    scanf("%s", ch);
    int sz = strlen(ch);
    for (i = 0; i <sz; i++) {
            if (ch[i] == 'A')
                sum1++;
            if (ch[i] == 'B')
                sum2++;
        }
        if (sum1 > sum2)
            printf("A\n");
        else if(sum1 < sum2)
            printf("B\n");
        else if(sum1==sum2)
            printf("E\n");

    }