4
10 4
15 1
19 3
20 1
 2
1 999999999
1000000000 1000000000
 67
1 1
3 8
4 10
7 8
9 2
10 1
11 5
12 8
13 4
16 6
18 3
19 3
22 5
24 6
27 5
28 3
29 3
30 5
32 5
33 10
34 7
35 8
36 5
41 3
42 2
43 5
46 4
48 4
49 9
52 4
53 9
55 1
56 4
59 7
68 7
69 4
71 9
72 10
74 5
76 4
77 9
80 7
81 9
82 5
83 5
84 9
85 7
86 9
87 4
88 7
89 10
90 3
91 5
92 10
93 5
94 8
95 4
96 2
97 10
98 1
99 3
100 1
101 5
102 4
103 8
104 8
105 8
 10
999999900 1000000000
999999901 1000000000
999999902 1000000000
999999903 1000000000
999999904 1000000000
999999905 1000000000
999999906 1000000000
999999907 1000000000
999999908 1000000000
999999909 1000000000
 35
1 7
3 11
6 12
7 6
8 5
9 11
15 3
16 10
22 2
23 3
25 7
27 3
34 5
35 10
37 3
39 4
40 5
41 1
44 1
47 7
48 11
50 6
52 5
57 2
58 7
60 4
62 1
67 3
68 12
69 8
70 1
71 5
72 5
73 6
74 4
 1
1000000000 1000000000
 2
100000000 1000000000
1000000000 1000000000
 10
7 12
10 2
12 2
15 1
19 2
20 1
53 25
63 10
75 12
87 1
 3
1 1
1000 1000
1000000000 1000000000
 40
1 1
2 1
3 1
4 1
5 1
6 1
7 1
8 1
9 1
10 1
11 1
12 1
13 1
14 1
15 1
16 1
17 1
18 1
19 1
20 1
21 1
22 1
23 1
24 1
25 1
26 1
27 1
28 1
29 1
30 1
31 1
32 1
33 1
34 1
35 1
36 1
37 1
38 1
39 1
40 1

4
 2
 5
 2
 10
 1
 2
 9
 3
 2

import java.util.StringTokenizer;
import java.io.*;
public class wood{
	public static void main(String args[]) throws IOException {
      Reader in = new Reader();
      int n = in.nextInt();
      int arr[][] = new int[n+1][2];
      for(int i=0;i<n;i++) arr[i] = in.readArray(2);
      int dp[][] = new int[n][3];
      arr[n][0] = Integer.MAX_VALUE;
      dp[0][0] = 1;
      dp[0][1] = 1;
      dp[0][2] = 0;
      for(int i=1;i<n;i++){
          int l =  arr[i-1][0];
          int lh = arr[i-1][1];
          int r = arr[i+1][0];
          int c = arr[i][0];
          int h = arr[i][1];
          if(c-l>h){
              if(c-l-lh>h) dp[i][0] = Math.max(dp[i-1][0],Math.max(dp[i-1][1],dp[i-1][2])) + 1;
              else dp[i][0] = Math.max(dp[i-1][0],dp[i-1][2]) + 1;
           }
          else dp[i][0] = Math.max(dp[i-1][0],Math.max(dp[i-1][1],dp[i-1][2]));
          if(r-c>h){
              dp[i][1] = Math.max(dp[i-1][0],Math.max(dp[i-1][1],dp[i-1][2]))+1;
          }
          else dp[i][1] = Math.max(dp[i-1][0],Math.max(dp[i-1][1],dp[i-1][2]));
          dp[i][2] = Math.max(dp[i-1][0],Math.max(dp[i-1][1],dp[i-1][2]));
          //System.out.println(dp[i][0]+" "+dp[i][1]+" "+dp[i][2]);
    }
      System.out.println(Math.max(dp[n-1][0],Math.max(dp[n-1][1],dp[n-1][2])));
  }
	static class Reader{
		private BufferedReader rd;
		private StringTokenizer tk;
		Reader(){
			rd = new BufferedReader(new InputStreamReader(System.in));
			tk = null;
		}
		public String next() {
			while(tk==null || !tk.hasMoreElements()) {
				try {
					tk = new StringTokenizer(rd.readLine());
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			return tk.nextToken();
		}
		private int nextInt(){
			return Integer.parseInt(next());
		}
		private double nextdouble() {
			return Double.parseDouble(next());
		}
		private float nextfloat() {
			return Float.parseFloat(next());
		}
		private  int[] readArray(int n) {
			int arr[] = new int[n];
			for(int i=0;i<n;i++) arr[i] = nextInt();
			return arr;
		}
	}
}

