def main():
    N = int(input())
    C = tuple(map(int, input().split()))

    if N == 1:
        if C[0] == 1:
            ans = 'A'
        if C[0] == 0 or C[0] % 2:
            ans = 'B'
        else:
            ans = 'A'
    else:
        i = 0
        for j in C:
            i += j % 2

        if i % 2:
            ans = 'A'
        else:
            ans = 'B'

    print(ans)

main()