You are given two linked lists: `list1` and `list2` of sizes `n` and `m` respectively.

Remove `list1`'s nodes from the `ath` node to the `bth` node, and put `list2` in their place.

The blue edges and nodes in the following figure indicate the result:

Build the result list and return its head.

Example 1:

    Input: list1 = [0,1,2,3,4,5], a = 3, b = 4, list2 = [1000000,1000001,1000002]
    Output: [0,1,2,1000000,1000001,1000002,5]
    Explanation: We remove the nodes 3 and 4 and put the entire list2 in their place. The blue edges and nodes in the above figure indicate the result.

Example 2:

    Input: list1 = [0,1,2,3,4,5,6], a = 2, b = 5, list2 = [1000000,1000001,1000002,1000003,1000004]
    Output: [0,1,1000000,1000001,1000002,1000003,1000004,6]
    Explanation: The blue edges and nodes in the above figure indicate the result.

Constraints:

- `3 <= list1.length <= 104`
- `1 <= a <= b < list1.length - 1`
- `1 <= list2.length <= 104`