problem description said dragon will not use breath two times, but test 21 there is at least three breath in the input file...

hope admin can fix it..

oops I misunderstood "in a row"
is "in a row" means cosecutive??

I think we must use O(2^20*10) dynamic programming ,because there maybe two breath in a row

brute_force will definitely got TLE

wa haha Accepted...