Swap First Last

Swap first and last elements of a list in place.

Your task

Implement this function:

def swap_first_last(l: list) -> None:

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

This function changes its argument in place and returns nothing; the updated l is what gets printed.

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

Example

Input

[1, 2, 3, 4]

Output

[4, 2, 3, 1]