source_code: import java.util.*;
  import java.io.*;
  import static java.lang.System.in;
  
  public class Main {
      public static void main(String[] args)throws IOException{
          Scanner sc = new Scanner(System.in);
          int n = sc.nextInt();
          int[][] point = new int[n][];
          for(int i=0;i<n;i++) point[i] = new int[]{sc.nextInt(),sc.nextInt()};
          Arrays.sort(point,(a,b)->((a[0]-a[1])-(b[0]-b[1])));
          TreeMap<Integer,Integer> tm = new TreeMap<>();
          int ans = 0;
          for(int i=n-1;i>=0;i--){
              int x = point[i][0], w = point[i][1];
              Map.Entry<Integer,Integer> cur =  tm.ceilingEntry(x+w);
              int curRes;
              if(cur==null) curRes = 1;
              else curRes = cur.getValue()+1;
              ans = Math.max(ans,curRes);
              Map.Entry<Integer,Integer> upper = tm.ceilingEntry(x-w);
              if(upper==null||upper.getValue()<curRes) tm.put(x-w,curRes);
              //Integer key = tm.
          }
          System.out.println(ans);
      }
  }
  