A Moment of Happiness

Limits 1s, 512 MB

Solving a problem during a programming contest is always a moment of happiness. During the CUET CSE fest programming contest, team $X’s$ solved status is denoted by a binary string $S$ of size $N$ where for all $(1 \leq i \leq N)$ , $S_i = 1$ means team $X$ has already solved this problem and $S_i = 0$ means they haven’t solved this yet. Recall that a binary string is a non-empty sequence of characters where each character is either 0 or 1.

After a few hours of the contest, judge pc suddenly started acting weirdly. When a team solves a problem, the next problem automatically gets accepted. In other words, if $X$ solves problem $i$ $(i\leq 1 \leq N)$ that is $S_i$ becomes $1$ then $S_{i+1}$ also becomes $1$ if $(i + 1 \leq N)$ .

Team $X$ found this fault and wants to make the best use of it. Your task is to find the minimum number of submissions team $X$ needs to make to solve all the problems. Here you can assume that if team $X$ makes a submission then it gets accepted.

Input

The first line contains the value of $N$ $(1\leq N \leq 10^5)$ — the length of the binary string.

The second line contains a binary string $S$ and for all $(1 \leq i \leq N)$ , $S_i$ is either $0$ or $1$ .

Output

Print a single integer — minimum number of submissions team $X$ needs to make to solve all the problems.

Samples

Input	Output
5 01001	2
First, team $X$ solves the first problem that is $X$ selects $i = 1$ and the string becomes 11001. Then, team $X$ solves the third problem that is $X$ selects $i = 3$ and the string becomes 11111.

Input	Output
5 11111	0