>>def nexts(*iters):
>> nexts = [i for i in iters]
while nexts:
>> t = nexts
try:
>> for n, i in enumerate(t):
if iter(i):
yield n
>> except:
>> t = next[:n] + next[n+1:]
nexts = t

>>for i in nexts([[1,1],[2,2],3]):
pass