this question is stupid... any average 10 years old kid could answer this....

I just wanna point out that... the constraints in this problem are not tight,
that's mean if I add one more ball into your problem (13 balls instead of 12),
this problem is still solvable....

pls post in chinese next time....

Sure I can, but I'll skip on this one...

I've already pointed out that I could solve this problem with 13 balls,
by the way, do you think the 13 balls problem is unsolvable ???
if no, how could you still not believe that I am able to solve the 12 balls problem...  

I could even prove that a 14 balls problem is unsolvable using simple mathematics...