Longest Shelf Run With At Most k Brands

A store shelf holds n items in a row, each labeled by an integer brand id. A restocking rule allows a contiguous stretch to mix at most k distinct brands. Find the length of the longest contiguous stretch that contains at most k distinct brand ids.

Input format

Line 1: two integers n and k. Line 2: n space-separated integers, the brand ids in shelf order.

Output format

A single integer: the length of the longest contiguous window with at most k distinct values.

Constraints

• 1 ≤ n ≤ 100000
• 1 ≤ k ≤ n
• 1 ≤ each brand id ≤ 1000000000