And again rice
Old man Vasyl, a prosperous Ukrainian farmer, has expanded his "rice fever" after a successful rice campaign. This time, he has ordered n batches of rice, each of a specific variety. Each batch can cover an area of 1 square meter. Vasyl owns a plot of land that measures k square meters. He firmly believes that rice will only thrive on a plot of k square meters if it contains exactly k different varieties. Therefore, he adheres strictly to this method of planting.
Your task is to determine how many plots of k square meters can be planted with rice.
Input
The first line contains two integers, n and k, where 1 ≤ n ≤ 10^5 and 1 ≤ k ≤ 10^5. The second line contains n natural numbers, each representing a rice variety, with values not exceeding 2 · 10^9.
Output
Output a single integer, which is the number of plots of k square meters that can be planted with rice.