Problem: In the last mission, MDCS has successfully shipped N AI robots to Mars. Before they start exploring, system initialization is required so they are arranged in a line. Every robot can be described with three numbers: position (x_i), radius of sight (r_i) and IQ (q_i).

Since they are intelligent robots, some of them will talk if they see each other. Radius of sight is inclusive, so robot can see other all robots in range [x_i - r_i, x_i + r_i]. But they don't walk to talk with anybody, but only with robots who have similar IQ. By similar IQ we mean that their absolute difference isn't more than K. 

Help us and calculate how many pairs of robots are going to talk with each other, so we can timely update their software and avoid any potential quarrel.

Input

The first line contains two integers, numbers N (1 ≤ N ≤ 10^5)  and K (0 ≤ K ≤ 20).

Next N lines contain three numbers each x_i, r_i, q_i (0 ≤ x_i,r_i,q_i ≤ 10^9) — position, radius of sight and IQ of every robot respectively.

Output

Output contains only one number — solution to the problem.

Example

Input

3 2
3 6 1
7 3 10
10 5 8


Output

1

Note

The first robot can see the second, but not vice versa. The first robot can't even see the third. The second and the third robot can see each other and their IQs don't differ more than 2 so only one conversation will happen.

Solution (in JAVA):

Solution:
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.*;

/**
 *
 */
public class A2 {
    static class Pair implements Comparable<Pair>{
        int x,l;

        public Pair(int x, int l) {
            this.x = x;
            this.l = l;
        }

        @Override
        public int compareTo(Pair o) {
            return Integer.compare(l, o.l);
        }
    }
    static class Robot implements Comparable<Robot>{
        int x,r,q;

        public Robot(int x, int r, int q) {
            this.x = x;
            this.r = r;
            this.q = q;
        }

        @Override
        public int compareTo(Robot o) {
            return Integer.compare(x, o.x);
        }
    }

    static class SubTask{
        Pair[] leftEnds;
        int xbound = 0;
        int lefti = 0;
        int sx[];
        Treap.Node tree;

        public SubTask(ArrayList<Pair> list) {
            int size = list.size();
            leftEnds = new Pair[size];
            sx = new int[size];
            int i = 0;
            for (Pair node : list) {
                leftEnds[i] = node;
                sx[i++] = node.x;
            }
            Arrays.sort(leftEnds);
            Arrays.sort(sx);
        }
    }
    static int bisectRight(int [] arr, int val, int lo, int hi){
        int low = lo;
        int high = hi;
        while (low < high) {
            int mid = (low + high) >>> 1;
            if (arr[mid] <= val)
                low = mid+1;
            else
                high = mid;
        }
        return low;
    }
    public static void main(String[] args) throws IOException {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st = new StringTokenizer(reader.readLine());
        int n = Integer.parseInt(st.nextToken());
        int k = Integer.parseInt(st.nextToken());
        int x[]= new int[n];
        int r[]= new int[n];
        int q[]= new int[n];
        Robot sx[]=new Robot[n];
        HashMap<Integer, ArrayList<Pair>> iqlm = new HashMap<>();
        HashMap<Integer, HashMap<Integer, Integer>> iqxc = new HashMap<>();
        for (int i = 0; i < n; i++) {
            st = new StringTokenizer(reader.readLine());
            x[i] = Integer.parseInt(st.nextToken());
            r[i] = Integer.parseInt(st.nextToken());
            q[i] = Integer.parseInt(st.nextToken());
            sx[i] = new Robot(x[i], r[i], q[i]);
            ArrayList<Pair> la = iqlm.computeIfAbsent(q[i], k1 -> new ArrayList<>());
            la.add(new Pair(x[i], x[i]-r[i]));
            HashMap<Integer, Integer> xm = iqxc.computeIfAbsent(q[i], k1 -> new HashMap<Integer, Integer>());
            xm.put(x[i], xm.getOrDefault(x[i], 0)+1);
        }
        HashMap<Integer, SubTask> subTasks = new HashMap<>();
        for (Map.Entry<Integer, ArrayList<Pair>> entry : iqlm.entrySet()) {
            subTasks.put(entry.getKey(), new SubTask(entry.getValue()));
        }
        Arrays.sort(sx);

        long ans = 0;
        for (int i = 0; i < n; i++) {
            int cx = sx[i].x;
            int rightBound = cx + sx[i].r;
            for (int iq = sx[i].q-k; iq <= sx[i].q+k; iq++) {
                SubTask subTask = subTasks.get(iq);
                if(subTask == null)
                    continue;
                Pair[] leftEnds = subTask.leftEnds;
                while(subTask.lefti < leftEnds.length && leftEnds[subTask.lefti].l <= cx) {
                    subTask.tree = Treap.insert(subTask.tree, new Treap.Node(leftEnds[subTask.lefti].x));
                    subTask.lefti++;
                }
                if(sx[i].q == iq){
                    subTask.tree = Treap.erase(subTask.tree, cx);
                }
                ans += Treap.bisectLeft(subTask.tree, rightBound+1);

            }
        }
        System.out.println(ans);
    }
    static public class Treap {
        static Random rgen = new Random();

        static class Node{
            Node l,r;
            Node parent;
            int count;
            int key, priority;

            public Node(int key) {
                this.key = key;
                priority = rgen.nextInt();
                this.count = 1;
            }

            public Node(int key, int priority) {
                this.key = key;
                this.priority = priority;
                this.count = 1;
            }
        }
        static void updParent(Node node, Node parent){
            if(node!= null)
                node.parent= parent;
        }

        static void updCnt(Node node){
            if(node!= null){
                node.count = 1;
                if (node.l!=null)
                    node.count+=node.l.count;
                if (node.r!=null)
                    node.count+=node.r.count;
            }
        }
        static Node[] split(Node root, int key){
            if(root == null)
                return new Node[]{null,null};
            Node[] split;
            if(key <= root.key){
                updParent(root.l, null);
                split = split(root.l, key);
                root.l = split[1];
                updParent(root.l, root);
                split[1] = root;
            } else {
                updParent(root.r, null);
                split = split(root.r, key);
                root.r = split[0];
                updParent(root.r, root);
                split[0] = root;
            }
            updCnt(root);
            return split;
        }

        static Node[] splitC(Node root, int C){ // key is a count
            if(root == null)
                return new Node[]{null,null};
            Node[] split;
            int cnt = count(root.l);
            if(C <= cnt){
                updParent(root.l, null);
                split = splitC(root.l, C);
                root.l = split[1];
                updParent(root.l, root);
                split[1] = root;
            } else {
                updParent(root.r, null);
                split = splitC(root.r, C-cnt-1);
                root.r = split[0];
                updParent(root.r, root);
                split[0] = root;
            }
            updCnt(root);
            return split;
        }

        static Node insert(Node root, Node node){
            if(root == null)
                return node;
            if(root.priority<node.priority){
                Node[] split = split(root, node.key);
                node.l=split[0];
                updParent(node.l, node);
                node.r=split[1];
                updParent(node.r, node);
                updCnt(node);
                return node;
            } else{
                if(node.key <= root.key){
                    root.l = insert(root.l, node);
                    updParent(root.l, root);
                } else {
                    root.r = insert(root.r, node);
                    updParent(root.r, root);
                }
                updCnt(root);
                return root;
            }
        }

        static Node insertC(Node root, Node node, int C){
            if(root == null)
                return node;
            if(root.priority<node.priority){
                Node[] split = splitC(root, C);
                node.l=split[0];
                updParent(node.l, node);
                node.r=split[1];
                updParent(node.r, node);
                updCnt(node);
                return node;
            } else{
                int cnt = count(root.l);
                if(C <= cnt){
                    root.l = insertC(root.l, node, C);
                    updParent(root.l, root);
                } else {
                    root.r = insertC(root.r, node, C-cnt-1);
                    updParent(root.r, root);
                }
                updCnt(root);
                return root;
            }
        }



        static int count(Node a) {
            return a == null ? 0 : a.count;
        }



        static Node merge(Node l, Node r){
            if(l==null)
                return r;
            if(r==null)
                return l;
            if(r.priority < l.priority){
                updParent(l.r, null);
                updParent(r, null);
                l.r = merge(l.r, r);
                updParent(l.r, l);
                updCnt(l);
                return l;
            }else{
                updParent(r.l, null);
                updParent(l, null);
                r.l = merge(l, r.l);
                updParent(r.l, r);
                updCnt(r);
                return r;
            }
        }

        static int bisectLeft(Node root, int keyBound){ //a[:rank] < bound <= a[rank:]
            int cnt = 0;
            while(root != null){
                if(keyBound <= root.key){
                    root = root.l;
                }else{
                    cnt++;
                    if(root.l != null)
                        cnt += root.l.count;
                    root = root.r;
                }
            }
            return cnt;
        }

        public static Node next(Node node) {
            if(node == null)
                return null;
            if(node.r != null){
                node = node.r;
                while(node.l != null)
                    node = node.l;
                return node;
            }else{
                while(true){
                    Node p = node.parent;
                    if(p == null)
                        return null;
                    if(p.l == node)
                        return p;
                    node = p;
                }
            }
        }

        public static Node min(Node root) {
            if(root == null)
                return null;
            while(root.l != null){
                root = root.l;
            }
            return root;
        }

        public static Node max(Node root) {
            if(root == null)
                return null;
            while(root.r != null){
                root = root.r;
            }
            return root;
        }

        public static Node prev(Node node) {
            if(node == null)
                return null;
            if(node.l != null){
                node = node.l;
                while(node.r != null)
                    node = node.r;
                return node;
            }else{
                while(true){
                    Node p = node.parent;
                    if(p == null)
                        return null;
                    if(p.r == node)
                        return p;
                    node = p;
                }
            }
        }

        static Node search(Node root, int key){
            while(root != null){
                if(root.key == key){
                    return root;
                }
                if(key < root.key){
                    root = root.l;
                }else{
                    root = root.r;
                }
            }
            return null; // not found
        }

        static Node searchC(Node root, int C){
            while(root != null){
                int cnt = count(root.l);
                if(C == cnt){
                    return root;
                }
                if(C < cnt){
                    root = root.l;
                }else{
                    C -= cnt+1;
                    root = root.r;
                }
            }
            return null; // not found...
        }

        static int rank(Node root, int key){ // arbitrary for non-unique keys
            int cnt = 0;
            while(root != null){
                if(root.key == key){
                    if(root.l != null)
                        cnt += root.l.count;
                    return cnt;
                }
                if(key < root.key){
                    root = root.l;
                }else{
                    cnt++;
                    if(root.l != null)
                        cnt += root.l.count;
                    root = root.r;
                }
            }
            return -cnt-1; // not found, but should be at cnt (-res-1)
        }

        static int rank(Node node){ // returns C
            if(node == null)
                return -1; // not found
            int cnt = count(node.l);
            while(node != null){
                if(node.parent != null && node.parent.r == node)
                    cnt += count(node.parent.l)+1;
                node = node.parent;
            }
            return cnt;
        }

        static Node erase(Node root, int key){
            if(root == null)
                return null;
            if(root.key == key){
                updParent(root.l, null);updParent(root.r, null);
                return merge(root.l, root.r);
            } else if(key < root.key){
                root.l = erase(root.l, key);
                updParent(root.l, root);
                updCnt(root);
                return root;
            } else {
                root.r = erase(root.r, key);
                updParent(root.r, root);
                updCnt(root);
                return root;
            }
        }

        static Node eraseC(Node root, int C){
            if(root == null)
                return null;
            int cnt = count(root.l);
            if(C == cnt){
                updParent(root.l, null);updParent(root.r, null);
                return merge(root.l, root.r);
            } else if(C < cnt){
                root.l = eraseC(root.l, C);
                updParent(root.l, root);
                updCnt(root);
                return root;
            } else {
                root.r = eraseC(root.r, C-cnt-1);
                updParent(root.r, root);
                updCnt(root);
                return root;
            }
        }


    }

}