21.py

# Definition for singly-linked list.
# class ListNode:
#     def __init__(self, x):
#         self.val = x
#         self.next = None


class ListNode:
    def __init__(self, x):
        self.val = x
        self.next =None
    


class Solution:
    def mergeTwoLists(self, l1, l2):
        """
        :type l1: ListNode
        :type l2: ListNode
        :rtype: ListNode
        """
        




if __name__=='__main__':
    sl = Solution()
    
        


        
            
            
            
        
        

        

        

        



if __name__=='__main__':
    
    start =ListNode(10)
    rr =start
    rr.next =ListNode(20)
    rr=rr.next
    rr.next = ListNode(30)
    rr=rr.next

    p=start
    while p!=None:
        print(p.val)
        p=p.next