You are given the heads of two singly linked lists, headA and headB, to determine whether the two lists intersect. If they intersect, return the node where the intersection begins. Otherwise, return NULL.

Note: Linked lists intersect if they share a common node in memory, not just a node with the same value.

Constraints:

• $1 ≤$ node.val $≤ 10^5$

• The number of nodes of $listA$ is in the $m$.

• The number of nodes of $listB$ is in the $n$ ...