3499. Maximize Active Section with Trade I

You are given a binary string s of length n, where: - '1' represents an active section. - '0' represents an inactive section. You can perform at most one trade to maximize the number of active sections in s. In a trade, you: - Convert a contiguous block of '1's that is surrounded by '0's to all '0's. - Afterward, convert a contiguous block of '0's that is surrounded by '1's to all '1's. Retu