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

def solve(n,trees):
    big = float('inf')
    small = float('-inf')
    res = 1
    trees[0].append("L")
    trees.append([big,big])
    for i in range(1,n):
        flag = True
        if trees[i - 1][-1] != "R":
            if trees[i][0] - trees[i][1] > trees[i - 1][0]:
                flag = False
                res += 1
                trees[i].append("L")
        if flag:
            if trees[i - 1][-1] == "R" and trees[i][0] - trees[i][1] > trees[i - 1][0] + trees[i - 1][1]:
                res += 1
                trees[i].append("L")

            elif trees[i][0] + trees[i][1] < trees[i + 1][0]:
                res += 1
                trees[i].append("R")
    # print(trees)
    return res

def main():
    t = int(input())
    trees = []
    for i in range(t):        
        d = input()
        d = [int(i) for i in d.split()]       
        a = d[0]
        b = d[1]
        trees.append([a,b])        
    ans = solve(t,trees) 
    print(ans)     
        # for i in ans:
        #     print(i,end = "")
        # print()  
main()

x = [0]