Description

Given a non-empty binary string $S$ with non-zero length.

Find a non-empty contiguous substring $T$ of $S$ such that the number of $0$ in the substring minus the number of $1$ in the substring is maximized.

You only need to output this maximum value.

Input Format

One line containing a binary string representing $S$.

Output Format

One line containing one number representing the answer.

0111100101

2

Hint

Let $|S| = n$.

Constraints

For $100\%$ of the testdata, $1 \le n \le {10}^5$.

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