Given the beginning of a singly linked list head, reverse the list, and return the new beginning of the list.

Example 1:

Input: head = [0,1,2,3]

Output: [3,2,1,0]

Example 2:

Input: head = []

Output: []

Constraints:

• 0 <= The length of the list <= 1000.
• -1000 <= Node.val <= 1000