public class UniqueIntegers {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n = scanner.nextInt();
        int k = scanner.nextInt();
        Set<Integer> set = new HashSet<>();
        int[] arr = new int[n];
        
        for (int i = 0; i < n; i++) {
            arr[i] = scanner.nextInt();
        }
        
        int maxUnique = 0;
        for (int i = 0; i <= n - k; i++) {
            set.clear();
            for (int j = i; j < i + k; j++) {
                set.add(arr[j]);
            }
            maxUnique = Math.max(maxUnique, set.size());
        }
        
        System.out.println(maxUnique);
    }
}