def fib_ls(n):
    """
    This return a list with n items.
    For example if n=5, this returns [0, 1, 1, 2, 3]
    and its length of the list is 5
    """
    fibo_ls = [0, 1]
    for _ in range(2, n):
        fibo_ls.append(fibo_ls[-1] + fibo_ls[-2])
    return fibo_ls