3009：Go Fishing

This summer vacation, FZU-ACM members get together for training in the name of dream. Some of them like fishing. One afternoon M members of them go fishing together around the lake, they bring many buckets with them and put their fish in either one of N buckets, they can only remember the number of fish they catch, and the number of fish in every bucket. When the sun went down, everyone wants to take away the part belonging to him, so they need to split the N buckets into more buckets (here we can assume the number of buckets they own is unlimited). They want to minimize the times of split. They are so tired, so ask you to help them solve their puzzle. Each time they can only split the fish in one bucket into two buckets.

The input consists of several test cases. The first line of each case contains two integers N,M.(1<=N,M<8)
N representing the number of buckets they put their fish in, and M representing the number of ACM members that go fishing.
The next line contains N integers representing the number of fish in each bucket.
The next line contains M integers representing the number of fish each ACM member catch.

Output the minimal times they need to split the fish.