Merge Two Sorted Lists

You are given the heads of two sorted lists of integers `list1` and `list2`. Merge the two lists into one sorted list. The list should be made by splicing together the nodes of the first two lists. Return the merged sorted list as space-separated integers. If the resulting list is empty, print nothing. ### Constraints - The number of nodes in both lists is in the range `[0, 50]`. - `-100 <= Node.val <= 100` - Both `list1` and `list2` are sorted in non-decreasing order. ### Input Format First line contains space-separated integers representing `list1` (or empty). Second line contains space-separated integers representing `list2` (or empty). ### Output Format Print the space-separated values of the merged sorted list.