Longest Consecutive Ones After a Single Flip

You are given a binary string S of length N. You are allowed to flip exactly one '0' to a '1'. After this operation, the contiguous sequence of '1's may merge with adjacent sequences of '1's. Formally, if the chosen '0' is between two segments of consecutive '1's with lengths L₁ and L₂, then the resulting contiguous block will have length \(L₁+1+L₂\). If there is no '0' in the string, the answer is simply N.

Your task is to determine the maximum possible length of a contiguous segment of '1's after performing at most one flip.

inputFormat

The first line of the input contains an integer T denoting the number of test cases. Each test case consists of a single line containing an integer N and a binary string S of length N separated by a space.

For example:

3
3 101
5 11010
6 000000

outputFormat

For each test case, output one line containing an integer – the maximum length of the contiguous segment of '1's that can be obtained after flipping exactly one '0'.

For the sample input above, the output should be:

3
4
1

## sample

3
3 101
5 11010
6 000000

3
4
1

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