Replace Linked List on Index

You are given two linked lists a and b as well as integers lo and hi.

Remove a’s nodes from indices (0-indexed) [lo, hi] inclusive and insert b in this place.

Constraints

• 0 ≤ n ≤ 100,000 where n is the number of nodes in a
• 0 ≤ m ≤ 100,000 where m is the number of nodes in b

https://binarysearch.com/problems/Replace-Linked-List-on-Index

Examples

Example 1

Input

• a =

• b =

• lo = 1
• hi = 2

Output

• answer =

Explanation

We removed nodes 2 and 3 since their indices are in [1, 2]. In its place we inserted b.

Example 2

Input

• a =

• b =

• lo = 0
• hi = 2

Output

• answer =

Explanation

We removed every node of a and inserted b.

Solution