#!/usr/local/bin/python2
from itertools import chain
chain_from_iterable = chain.from_iterable

l = [[1,2,3,4,5],[6,7,8,9,0],[1,2,3,4,5],[6,7,8,9,0],[1,2,3,4,5]]
for i in xrange(10000):
  list(sorted(chain_from_iterable([j for j in l])))