package main

type ListNode struct {
	Val int
	Next *ListNode
}

func getIntersectionNode(headA, headB *ListNode) *ListNode {
	mp := map[*ListNode]bool{}
	for headA != nil {
		mp[headA] = true
		headA = headA.Next
	}
	for headB != nil {
		if ok := mp[headB] ; ok {
			return headB
		}
		headB = headB.Next
	}
	return nil
}