p02918 AtCoder Beginner Contest 140 - Face Produces Unhappiness
There are N people standing in a queue from west to east.

Given is a string S of length N representing the directions of the people. The i-th person from the west is facing west if the i-th character of S is `L`, and east if that character of S is `R`.

A person is happy if the person in front of him/her is facing the same direction. If no person is standing in front of a person, however, he/she is not happy.

You can perform the following operation any number of times between 0 and K (inclusive):

Operation: Choose integers l and r such that 1 \leq l \leq r \leq N, and rotate by 180 degrees the part of the queue: the l-th, (l+1)-th, ..., r-th persons. That is, for each i = 0, 1, ..., r-l, the (l + i)-th person from the west will stand the (r - i)-th from the west after the operation, facing east if he/she is facing west now, and vice versa.

What is the maximum possible number of happy people you can have?

Constraints

* N is an integer satisfying 1 \leq N \leq 10^5.
* K is an integer satisfying 1 \leq K \leq 10^5.
* |S| = N
* Each character of S is `L` or `R`.

Input

Input is given from Standard Input in the following format:


N K
S


Output

Print the maximum possible number of happy people after at most K operations.

Examples

Input

6 1
LRLRRL


Output

3


Input

13 3
LRRLRLRRLRLLR


Output

9


Input

10 1
LLLLLRRRRR


Output

9


Input

9 2
RRRLRLRLL


Output

7
```python
n, k = map(int, input().split())
s = input()
h = sum(1 for i in range(n-1) if s[i] == s[i+1])
print(min(n-1, h+k*2))
```