import java.util.*;

/*
 * public class ListNode {
 *   int val;
 *   ListNode next = null;
 * }
 */

public class Solution {
    /**
     * 
     * @param head ListNode类 
     * @return ListNode类
     */
    public ListNode insertionSortList (ListNode head) {
        // write code here
        if(null==head||null==head.next){
            return head;
        }

        ListNode dummy=new ListNode(0);
        ListNode curr=head;

        while(curr!=null){
            ListNode nextTemp=curr.next;

            ListNode prev=dummy;
            ListNode sourtedCurr=dummy.next;

            while(sourtedCurr!=null&&sourtedCurr.val<curr.val){
                prev=sourtedCurr;
                sourtedCurr=sourtedCurr.next;
            }

            curr.next=sourtedCurr;
            prev.next=curr;

            curr=nextTemp;
        }

        return dummy.next;
    }
}