n = int(input())

def get(n):
    if n < 1:
        return None
    if n == 1:
        return ''
    if (n - 1) % 2 == 0:
        curr = get((n - 1) // 2)
        if curr != None:
            return curr + 'A'
    if (n - 1) % 3 == 0:
        curr = get((n - 1) // 3)
        if curr != None:
            return curr + 'B'
    return None

print(get(n) or '')