#!/usr/bin/python
# by Emile Van Sebille

if True:
    a = [1, 1, 2, 4, 6, 8, 9]
    b = [1, 3, 4, 5, 6, 7, 8]

    def popwhile(l,t):
       r = []
       while l[:1] == t:
         r.append(l.pop(0))
       return r

    while bool(a or b):
       m = min(a[:1],b[:1]) or max(a[:1],b[:1])
       print popwhile(a,m), popwhile(b,m)