A walking route passes n landmarks in order, each with an integer type id. A guide wants to know how many contiguous segments of the route visit exactly k distinct landmark types. Count those segments.
Input format
Line 1: two integers n and k.
Line 2: n space-separated integers, the landmark type ids in route order.
Output format
A single integer: the number of contiguous subarrays containing exactly k distinct values.
Constraints
- 1 ≤ n ≤ 100000
- 1 ≤ k ≤ n
- 1 ≤ each type id ≤ 1000000000