source_code: import java.io.*;
  import java.util.*;
  public class j
  {
  public static void main(String a[])throws IOException
  {
  BufferedReader b=new BufferedReader(new InputStreamReader(System.in));
  int k=0,i=0,j=0,n=0,p=0,t=0;
  String s;
  s=b.readLine();
  StringTokenizer c=new StringTokenizer(s);
  n=Integer.parseInt(c.nextToken());
  k=Integer.parseInt(c.nextToken());
  int d[]=new int[n];
  int e[]=new int[n];
  for(i=0;i<n;i++)
  {
  s=b.readLine();
  StringTokenizer z=new StringTokenizer(s);
  d[i]=Integer.parseInt(z.nextToken());
  e[i]=Integer.parseInt(z.nextToken());
  }
  for(i=0;i<n-1;i++)
  {
  for(j=i+1;j<n;j++)
  {
  if(d[j]<d[i])
  {
  t=d[j];
  d[j]=d[i];
  d[i]=t;
  t=e[j];
  e[j]=e[i];
  e[i]=t;
  }
  }
  }
  for(i=0;i<n-1;i++)
  {
  if(((d[i+1]-e[i+1]/2.0)-(d[i]+e[i]/2.0))>k)
  p+=2;
  if(((d[i+1]-e[i+1]/2.0)-(d[i]+e[i]/2.0))==k)
  p++;
  }
  System.out.print(p+2);
  }
  }