#include<cstdio>

#include<algorithm>

#include<queue>

using namespace std;

priority_queue<int,vector<int>,greater<int> > q;

struct node{

	int l,r;

}e[1000005];

bool cmp(node a,node b){

	return a.l<b.l;

}

int main(){

	int n,m;

	scanf("%d%d",&n,&m);

	for (int i=1; i<=n; i++){

		int x,y;

		scanf("%d%d",&x,&y);

		e[i]=(node){x,x+y};

	}

	sort(e+1,e+n+1,cmp);

	q.push(e[1].r+m);

	int ans=0;

	for (int i=2; i<=n; i++){

		while (!q.empty() && q.top()<e[i].l) q.pop();

		if (!q.empty()){

			int now=q.top();

			if (e[i].l>=now-m){

				ans++;

				q.pop();

			}

		}

		q.push(e[i].r+m);

	}

	printf("%d\n",ans);

	return 0;

}