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

#question3
import sys
from math import *
import builtins

input = sys.stdin.readline


def print(x, end='\n'):
    sys.stdout.write(str(x) + end)


# IO helpers
def get_int():
    return int(input())


def get_list_ints():
    return list(map(int, input().split()))


def get_char_list():
    s = input()
    return list(s[:len(s) - 1])


def get_tuple_ints():
    return tuple(map(int, input().split()))


def print_iterable(p):
    print(" ".join(map(str, p)))


def binary_search(arr, x):
    low = 0
    high = len(arr) - 1
    mid = 0
    while low <= high:
        mid = (high + low) // 2
        if arr[mid] < x:
            low = mid + 1
        elif arr[mid] > x:
            high = mid - 1
        else:
            return mid
    return high
def wood(listc,l):
    if l==1:
        return 1
    elif l==2:
        return 2
    else:
        stay=[0,1]
        if listc[1][0]-listc[0][0]>listc[1][1]:
            left=[1,2]
        else:
            left=[1,1]
        right=[1,2]
        for i in range(2,l):
            if listc[i][0]-listc[i-1][0]<=listc[i][1]:
                left.append(0)
                if listc[i][0]-listc[i-1][0]>listc[i-1][1]:
                    right.append(max(stay[i-1],left[i-1],right[i-1])+1)
                    stay.append(max(stay[i-1],left[i-1],right[i-1]))
                else:
                    right.append(max(stay[i-1],left[i-1])+1)
                    stay.append(max(stay[i-1],left[i-1]))
            elif listc[i][0]-listc[i-1][0]>listc[i-1][1]+listc[i][1]:
                left.append(max(stay[i-1],left[i-1],right[i-1])+1)
                right.append(max(stay[i-1],left[i-1],right[i-1])+1)
                stay.append(max(stay[i-1],left[i-1],right[i-1]))
            else:
                left.append(max(stay[i-1],left[i-1])+1)
                if listc[i][0]-listc[i-1][0]>listc[i-1][1]:
                    right.append(max(stay[i-1],left[i-1],right[i-1])+1)
                    stay.append(max(stay[i-1],left[i-1],right[i-1]))
                else:
                    right.append(max(stay[i-1],left[i-1])+1)
                    stay.append(max(stay[i-1],left[i-1]))
        return(max(stay[-1],left[-1],right[-1]))




def main(): 
    n=get_int()
    alist=[]
    for i in range(n):
        alist.append(get_list_ints())
    print(wood(alist,n))
    pass
    
if __name__ == '__main__':
    main()