SP28308 ADACLEAN - Ada and Spring Cleaning

Ada the Ladybug has decided to do some "Spring Cleaning". As you might know, she keeps a TODO list. She is very sparing so she keeps all her activities as one string. You might get very confused while reading the string but she has a system - every activity has length exactly **K** characters. Sadly, as new activities were added to the list many duplicities appeared. Now it is time to find out how many **unique** activities are in her TODO list.

First line contains **T**, number of test-cases. Each test-case begins with **N, K**, **1 , length of string and length of activites respectively.** Next line consists of string of length **N**, consisting of lowercase letters. The sum of lengths of strings among all test-cases won't exceed **3\*10 $ ^{5} $**

For each test-case, print the number of unique substrings of length **K**