AtCoder Inc. sells [T-shirts with its logo](https://suzuri.jp/AtCoder/5510290/t-shirt/s/ash).
You are given Takahashi's schedule for $N$ days as a string $S$ of length $N$ consisting of `0`, `1`, and `2`.
Specifically, for an integer $i$ satisfying $1\leq i\leq N$,
* if the $i$\-th character of $S$ is `0`, he has no plan scheduled for the $i$\-th day;
* if the $i$\-th character of $S$ is `1`, he plans to go out for a meal on the $i$\-th day;
* if the $i$\-th character of $S$ is `2`, he plans to attend a competitive programming event on the $i$\-th day.
Takahashi has $M$ plain T-shirts, all washed and ready to wear just before the first day.
In addition, to be able to satisfy the following conditions, he will buy several AtCoder logo T-shirts.
* On days he goes out for a meal, he will wear a plain or logo T-shirt.
* On days he attends a competitive programming event, he will wear a logo T-shirt.
* On days with no plans, he will not wear any T-shirts. Also, he will wash all T-shirts worn at that point. He can wear them again from the next day onwards.
* Once he wears a T-shirt, he cannot wear it again until he washes it.
Determine the minimum number of T-shirts he needs to buy to be able to wear appropriate T-shirts on all scheduled days during the $N$ days. If he does not need to buy new T-shirts, print $0$.
Assume that the purchased T-shirts are also washed and ready to use just before the first day.
## Constraints
* $1\leq M\leq N\leq 1000$
* $S$ is a string of length $N$ consisting of `0`, `1`, and `2`.
* $N$ and $M$ are integers.
## Input
The input is given from Standard Input in the following format:
$N$ $M$
$S$
[samples]