from sys import setrecursionlimit
setrecursionlimit(10**6)


def dfs(N):
    if N == 1:
        return ('', True)
    if (N - 1) % 2 == 0:
        res = dfs((N - 1) // 2)
        if res[1]:
            return (res[0] + 'A', True)
    if (N - 1) % 3 == 0:
        res = dfs((N - 1) // 3)
        if res[1]:
            return (res[0] + 'B', True)
    return ('', False)


print(dfs(int(input()))[0])