There are $N$ seats in a row, numbered $1, 2, \ldots, N$.

The state of the seats is given by a string $S$ of length $N$ consisting of # and .. If the $i$-th character of $S$ is #, it means seat $i$ is occupied; if it is ., seat $i$ is unoccupied.

Find the number of integers $i$ between $1$ and $N - 2$, inclusive, that satisfy the following condition:

• Seats $i$ and $i + 2$ are occupied, and seat $i + 1$ is unoccupied.

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

$N$

$S$

• $N$ is an integer satisfying $1 \leq N \leq 2 \times 10^5$.
• $S$ is a string of length $N$ consisting of # and ..

$i = 1$ and $4$ satisfy the condition, so the answer is $2$.