There are some fish in a bucket. Three fishermen come up to the bucket in turn. The first one tries to divide them into groups of three, but finds there is one left over, so he takes one and a third of the remaining fish. The next fisherman comes to the bucket, tries to divide the fish into three, finds there is one left over, so takes this and a third of the remaining fish. The third fisherman does the same. What is the minimum number of fish in the bucket to start with?