public static void findFreq(int arr[],int k) {
	
	
	HashSet<Integer> set = new HashSet<Integer>();
	
	int n = arr.length;
	int i=0,j=0;
	int wind=0;
	
	while(i<=n-k && wind<k) {
		
		set.add(arr[j]);
		
		if(wind == k-1) {
		   System.out.println(set.size());
		   set.clear();
		   wind=0;
		   i++;
		   j=i;
		   
		}
		else {
			
			j++;
			wind++;
			
		}
	}
	
}

public static void main(String as[]) {
	int arr[] = {10,10,5,3,10,5};
	findFreq(arr,3);

}