走完整条链一共几个

运行下面这段程序：

class Node:
    def __init__(self, name):
        self.name = name
        self.next = None

def build(names):
    head = None
    for x in reversed(names):
        nd = Node(x)
        nd.next = head
        head = nd
    return head

head = build(["阿岚", "小满", "阿泰", "南风"])
cur = head
n = 0
while cur is not None:
    n += 1
    cur = cur.next
print(n)