CF446A DZY Loves Sequences

DZY has a sequence $ a $ , consisting of $ n $ integers. We'll call a sequence $ a_{i},a_{i+1},...,a_{j} $ $ (1

The first line contains integer $ n (1

In a single line print the answer to the problem — the maximum length of the required subsegment.

You can choose subsegment $ a_{2},a_{3},a_{4},a_{5},a_{6} $ and change its 3rd element (that is $ a_{4} $ ) to 4.