The definition of an 11/22 string in this problem is the same as in Problems A and E.

A string $T$ is called an 11/22 string when it satisfies all of the following conditions:

• $|T|$ is odd. Here, $|T|$ denotes the length of $T$.
• The $1$-st through $(\frac{|T|+1}{2} - 1)$-th characters are all 1.
• The $(\frac{|T|+1}{2})$-th character is /.
• The $(\frac{|T|+1}{2} + 1)$-th through $|T|$-th characters are all 2.

For example, 11/22, 111/222, and / are 11/22 strings, but 1122, 1/22, 11/2222, 22/11, and //2/2/211 are not.

You are given a string $S$ of length $N$ consisting of 1, 2, and /, where $S$ contains at least one /.
Find the maximum length of a (contiguous) substring of $S$ that is an 11/22 string.

The input is given from Standard Input in the following format:

$N$

$S$

Print the maximum length of a (contiguous) substring of $S$ that is an 11/22 string.

• $1 \leq N \leq 2 \times 10^5$
• $S$ is a string of length $N$ consisting of 1, 2, and /.
• $S$ contains at least one /.

The substring from the $2$-nd to $6$-th character of $S$ is 11/22, which is an 11/22 string. Among all substrings of $S$ that are 11/22 strings, this is the longest. Therefore, the answer is $5$.