Intersection of Linked List Problem Statement

You are provided with two singly linked lists of integers. These lists merge at a node of a third linked list.

Your task is to determine the data of the node where merging begins. If there is no intersection, return -1.

Example:

Input Format:

The input format consists of three lines, each representing a singly linked list.
Each line contains the elements of a singly linked list separated by a space and terminated by -1.
For instance, the first linked list might look like: a1 a2 ... an c1 -1.
The second line could be: b1 b2 ... bm c1 -1.
The third line might be: c2 c3 ... ck -1.

Output Format:

Your output should be a single line that contains the data of the first merged node.
If there is no intersection, output should be -1.
You do not need to print anything explicitly; it is handled for you.

Constraints:

• 0 ≤ N ≤ 10⁵
• 0 ≤ M ≤ 10⁵
• 0 ≤ K ≤ 10⁵
• -10⁹ ≤ data ≤ 10⁹, and data ≠ -1
• Time Limit: 1 second