#include <stdio.h>
#include <stdlib.h>

//解法三

int main()
{
    char ch = 0;
    int flag = 0;
    while (((ch = getchar()) != '0') && ch != EOF)
    {
        if (ch == 'A')
        {
            flag++;
        }
        else if (ch == 'B')
        {
            flag--;
        }
    }
    if (flag > 0)
    {
        printf("A\n");
    }
    else if (flag < 0)
    {
        printf("B\n");
    }
    else if (flag == 0)
    {
        printf("E\n");
    }

    return 0;
}

/*

//解法二:

int main()
{
    int flag = 0;
    char arr[100] = { 0 };
    gets_s(arr, 100);
    int i = 0;
    while (arr[i] != '0')
    {
        if (arr[i] == 'A')
        {
            flag++;
        }
        else if (arr[i] == 'B')
        {
            flag--;
        }
        i++;
    }
    if (flag < 0)
    {
        printf("B\n");
    }
    else if (flag == 0)
    {
        printf("E\n");
    }
    else
    {
        printf("A\n");
    }

    return 0;
}

*/

/*

//解法一:

int main()
{
    //用于记录A,B的票数
    int count_a = 0;
    int count_b = 0;
    char arr[100] = { 0 };
    //输入
    gets_s(arr, 100);
    int i = 0;
    while (arr[i] != '0')
    {
        if (arr[i] == 'A')
        {
            count_a++;
        }
        else if (arr[i] == 'B')
        {
            count_b++;
        }

        i++;
    }

    if (count_a > count_b)
    {
        printf("A\n");
    }
    else if (count_a < count_b)

    {
        printf("B\n");
    }
    else
    {
        printf("E\n");
    }

    return 0;
}

*/