101841: [AtCoder]ABC184 B - Quizzes
Description
Score : $200$ points
Problem Statement
Takahashi will answer $N$ quiz questions.
Initially, he has $X$ points. Each time he answers a question, he gains $1$ point if his answer is correct and loses $1$ point if it is incorrect.
However, there is an exception: when he has $0$ points, he loses nothing for answering a question incorrectly.
You will be given a string $S$ representing whether Takahashi's answers are correct.
If the $i$-th character of $S$ from the left is o
, it means his answer for the $i$-th question is correct; if that character is x
, it means his answer for the $i$-th question is incorrect.
How many points will he have in the end?
Constraints
- $1 \le N \le 2 \times 10^5$
- $0 \le X \le 2 \times 10^5$
- $S$ is a string of length $N$ consisting of
o
andx
.
Input
Input is given from Standard Input in the following format:
$N$ $X$ $S$
Output
Print the number of points Takahashi will have in the end.
Sample Input 1
3 0 xox
Sample Output 1
0
Initially, he has $0$ points.
He answers the first question incorrectly but loses nothing because he has no point.
Then, he answers the second question correctly, gains $1$ point, and now has $1$ point.
Finally, he answers the third question incorrectly, loses $1$ point, and now has $0$ points.
Thus, he has $0$ points in the end. We should print $0$.
Sample Input 2
20 199999 oooooooooxoooooooooo
Sample Output 2
200017
Sample Input 3
20 10 xxxxxxxxxxxxxxxxxxxx
Sample Output 3
0