def collatz(n):
    steps = 0
    print(n, end="")
    while n != 1:
        if n % 2 == 0:
            n = n // 2
        else:
            n = 3 * n + 1
        steps = steps + 1
        print(" ->", n, end="")
    print()
    print("ステップ数:", steps)
    return steps

collatz(6)
collatz(27)
