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

    ListNode(int val) {
        this.val = val;
    }
}*/
public class Solution {       
    public ListNode Merge(ListNode list1,ListNode list2) {    
        if(list1==null&&list2==null) return null;
        ListNode newLN = null;
        ListNode T = null; //合併後的新連結串列
        int temp = 0;
        boolean boo = false; //判斷返回連結串列的第一個節點
        while(list1!=null||list2!=null){
            temp = 0;
            if(list1!=null&&list2!=null){
                temp = list1.val<=list2.val?list1.val:list2.val;
                if(temp==list1.val) list1 = list1.next;
                else list2 = list2.next;
            }                
            else if(list1!=null){
                temp = list1.val;
                list1 = list1.next;
            }
            else {
                temp = list2.val;
                list2 = list2.next;
            }             
            if(boo==false) {     
            	newLN = new ListNode(temp);
            	T = newLN;
            	boo = true;                        	           	
            }
            newLN = (newLN.next = new ListNode(temp));    
        }
        /*while(T.next!=null) {
    		System.out.print(T.next.val+" ");
    		T = T.next;
    	}*/
    	//System.out.println();
        return T.next;
    }

    
}