import java.util.*;
class Main{
   
    public static void main (String[] args) {
        int [] arr={0,1,2,3,4,5,6,7,8};
        int k=6;
        int sum=0,count=0;
       HashMap<Integer,Integer> map=new HashMap<>();
       map.put(0,1);
       for(int i : arr){
           sum+=i;
           if(map.containsKey((sum-k))){
               count+=map.get((sum-k));
           }
           map.put(sum,map.getOrDefault(sum,0)+1);
       }
       System.out.println(count);
    }
}