合并两个有序链表，要求输入数据: list_first{56,67,78,89,90}； list_second{34,45,56,87,98,100} 输出合并后的链表 -Merge two sorted linked list to enter data: list_first {56,67,78,89,90} list_second {34,45,56,87,98,100} output the merged linked list