All But the Last

In a throwback to CT days, you have to write one of the basic list functions.

Write a function named init that accepts a list L as argument. If the list is non-empty and has size n, it should return the first n - 1 elements as a list. If the list is empty, it should return None.

Note that if L has just one element, init(L) should return the empty list.

You do not have to accept input from the user or print anything to the console. You just have to write the function definition.

Example

init([1, 2, 3])  ->  [1, 2]
init([7])        ->  []
init([])         ->  None

Your task

Implement this function:

def init(L):

Write the function only — the arguments are read for you and the return value is printed automatically.

Arguments arrive as one Python literal per line, in this order: L.

Example

Input

[]

Output

None