We have a string of length n, which consist only UPPER and LOWER CASE characters and we have a number k (always less than n and greater than 0). We can make at most k changes in our string such that we can get a sub-string of maximum length which have all same characters.

**Input:**

The first line of the input contains an integer T which denotes the number of test cases to follow. Each test case contains space separated 2 integers n and k. Next line has a string of length n.

**Output:**

Print an integer which denotes the maximum length possible.

**Constraints:**

1<=T<=100

1<=n,k<=100000

1<=|S|<=100000

**Example:**

Input:

2

5 2

ABABA

6 4

HHHHHH

**Output:**

5

6

#### **For More Examples Use Expected Output**