import java.util.*;
class Main{
    public static boolean find(int [] arr,int k){
        HashMap<Integer,Integer>map=new HashMap<>();
        for(int i=0;i<arr.length;i++){
            if(map.containsKey(arr[i]) && i-map.get(arr[i])<=k){
                return true;
            }else{
                map.put(arr[i],i);
            }
        }
        return false;
    }
    public static void main (String[] args) {
        int [] arr={1,2,3,4,1,5};
        int k=3;
        if(find(arr,k)){
            System.out.println("true");
        }else{
            System.out.println("false");
        }
    }
}