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.Scanner;

public class Main {
	static Scanner s = new Scanner(System.in);	
	static int N = -1;
	static int[][] treeInfo = null;
	static int[][] process = null;
	public static void main(String[] args) {
		init();
		solve();
	}
	public static void init(){
		N = s.nextInt();
		treeInfo = new int[2][N];
		process = new int[N][3];
		process[0][0] = 1;  //0 : 왼, 1 : 가운 2 : 오
		process[0][1] = 0;
		process[0][2] = 1;
		for(int i=0;i<N;i++){
			treeInfo[0][i] = s.nextInt();//point
			treeInfo[1][i] = s.nextInt(); //height;
		}	
	}
	
	public static void solve(){
		for(int i=1;i<N;i++){
			solveForLeft(i);
			solveForMiddle(i);
			solveForRight(i);
		}
		int Max = 0;
		for(int i=0;i<3;i++){
			if(Max<process[N-1][i])
				Max = process[N-1][i];
		}
		System.out.println(Max);
	}
	public static void solveForLeft(int curIndex){
		int maxTree = 0;
		int prv_tree_point = treeInfo[0][curIndex-1];
		int prv_tree_height = treeInfo[1][curIndex -1];
		int cur_tree_point = treeInfo[0][curIndex];
		int cur_tree_height = treeInfo[1][curIndex];
		//내전이 왼쪽이었다
		if(prv_tree_point < cur_tree_point - cur_tree_height){
			maxTree = process[curIndex-1][0] +1>process[curIndex-1][1] + 1?
					process[curIndex-1][0] +1:process[curIndex-1][1] + 1;
		}
		else{
			maxTree = process[curIndex-1][0]>process[curIndex-1][1]?
					process[curIndex-1][0]:process[curIndex-1][1] ;
		}
		//내 전이 오른쪽이래
		if(prv_tree_point+prv_tree_height<cur_tree_point-cur_tree_height){
			maxTree = maxTree>process[curIndex-1][2]+1?maxTree:process[curIndex-1][2]+1;
		}else{
			maxTree = maxTree>process[curIndex-1][2]?maxTree:process[curIndex-1][2];
		}
		process[curIndex][0] = maxTree;
		
	}
	public static void solveForMiddle(int curIndex){
		int maxTree = 0;
		for(int i=0;i<3;i++){
			if(maxTree<process[curIndex-1][i])
				maxTree = process[curIndex-1][i];
		}
		process[curIndex][1] = maxTree;
		
	}
	public static void solveForRight(int curIndex){
		int maxTree = 0;
		for(int i=0;i<3;i++){
			if(maxTree<process[curIndex-1][i])
				maxTree = process[curIndex-1][i];
		}
		if(curIndex==N-1){
			process[curIndex][2] = maxTree+1;
			return;
		}
		int nxt_tree_point = treeInfo[0][curIndex+1];
		int nxt_tree_height = treeInfo[1][curIndex +1];
		int cur_tree_point = treeInfo[0][curIndex];
		int cur_tree_height = treeInfo[1][curIndex];
	
		
		if(nxt_tree_point>cur_tree_point+cur_tree_height){
			process[curIndex][2] = maxTree+1;
		}else{
			process[curIndex][2] = maxTree;
		}
	}
	
	
}