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

#include <bits/stdc++.h>
using namespace std;
bool vowel(char che) {
  if (che == 'A' || che == 'E' || che == 'I' || che == 'O' || che == 'U' ||
      che == 'Y') {
    return true;
  } else {
    return false;
  }
}
const long long mod = 1e9 + 7;
long long pw(long long a, long long b) {
  long long ans = 1;
  while (b) {
    if (b % 2 == 1) {
      ans *= a;
      ans %= mod;
    }
    b /= 2;
    a *= a;
    a %= mod;
  }
  return ans;
}
const int N = 1e6 + 5;
pair<long long, long long> p[N];
stack<int> sk;
string s, s1;
char o;
bool mark[N], h;
vector<long long> vt[N], vm, vs;
set<long long> st;
long long a[N], b[N], c[N], d[N], dp[N][3], dis, ps[N], tree, v[N];
void dfs(long long v, long long k) {}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  long long t, n, m, k = 0, f = 0, sum = 0, ans = 0;
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
  }
  dp[0][2] = 0;
  dp[0][0] = 1;
  if ((a[1] - a[0]) > b[0]) dp[0][1] = 1;
  long long mx = 1, mx1 = 1;
  a[n] = 1e17;
  for (int i = 1; i < n; i++) {
    dp[i][2] = mx;
    if ((a[i + 1] - a[i]) > b[i]) dp[i][1] = mx + 1;
    if ((a[i] - a[i - 1]) > (b[i] + b[i - 1]))
      dp[i][0] = mx + 1;
    else if ((a[i] - a[i - 1]) > b[i])
      dp[i][0] = mx1 + 1;
    mx = max(mx, max(dp[i][0], max(dp[i][1], dp[i][2])));
    mx1 = max(mx1, max(dp[i][0], max(dp[i - 1][1], dp[i][2])));
  }
  cout << mx << endl;
}
