import sys class ListNode: def __init__(self,value=0,next=None): self.value=value self.next=next def parse_input(s): if not s: return None head=ListNode(s[0]) cur=head for val in s[1:]: cur.next=ListNode(val) cur=cur.next return head headA=parse_input(list(map(int,input().strip().split()))) headB=parse_input(list(map(int,input().strip().split()))) curA=headA curB=headB res=[] while curA or curB: if curA and (not curB or curA.value<=curB.value): res.append(str(curA.value)) curA=curA.next elif curB: res.append(str(curB.value)) curB=curB.next print(" ".join(res))