def mystery(n):
    if n == 0:
        return 0
    elif n % 2 == 0:
        return mystery(n // 2)
    else:
        return 1 + mystery(n // 2)

print(mystery(19))

def secret(s):
    if len(s) <= 1:
        return s
    return secret(s[1:]) + s[0]

word = "DIM"
print(secret(word))