Reverse K-Group

Given the head of a linked list and an integer k, reverse the nodes of the list k at a time and return the modified list. If the number of nodes is not a multiple of k then left-out nodes in the end should remain as-is. You may not alter the values in the nodes, only the nodes themselves should be reversed. ### Input Format: - The first line contains an integer n, the number of nodes in the linked list. - The following n lines each contain a single integer, denoting the value of each node. - The last line contains the integer k. ### Output Format: - Print the values of nodes in the modified linked list in order, separated by spaces. ### Example: Input: 5 1 2 3 4 5 3 Output: 3 2 1 4 5