def rec(n):
    if n == 1:
        return ""
    if n % 2 == 1:
        res = rec(n // 2)
        if res is not None:
            return res + "A"
    if n % 3 == 1:
        res = rec(n // 3)
        if res is not None:
            return res + "B"
    else:
        return None


N = int(input())
print(rec(N))