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;
const long long M = 1e9 + 7;
long long IM = 1e17;
void PV(vector<long long> v) {
  for (long long i = 0; i < v.size(); i++) cout << v[i] << " ";
  cout << "\n";
}
void PA(long long v[], long long n) {
  for (long long i = 0; i < n; i++) cout << v[i] << " ";
  cout << "\n";
}
void IN(long long a[], long long n) {
  for (long long i = 0; i < n; i++) cin >> a[i];
}
inline void PTN(long long n = 1, long long a = 0, long long b = 0,
                long long c = 0) {
  if (n--) cout << a << " ";
  if (n--) cout << b << " ";
  if (n--) cout << c << " ";
  cout << "\n";
}
inline void open() {}
long long maxx(long long x, long long y, long long z) {
  return max(x, max(y, z));
}
long long dp[100005][3];
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  open();
  {
    long long n;
    cin >> n;
    vector<pair<long long, long long> > v;
    long long i, j, k, l, x, y;
    for (i = 0; i < n; i++) {
      cin >> x >> y;
      v.push_back({x, y});
    }
    v.push_back({IM, IM});
    long long ans = 0;
    dp[0][1] = 1;
    if (v[0].first + v[0].second < v[1].first) dp[0][2] = 1;
    for (i = 1; i < n; i++) {
      dp[i][1] = dp[i - 1][1];
      dp[i][2] = dp[i - 1][2];
      dp[i][0] = maxx(dp[i - 1][0], dp[i - 1][1], dp[i - 1][2]);
      if (v[i - 1].first < v[i].first - v[i].second)
        dp[i][1] = max(dp[i][1], dp[i - 1][0]) + 1;
      if (v[i - 1].first + v[i - 1].second < v[i].first - v[i].second)
        dp[i][1] = dp[i][0] + 1;
      if (v[i].first + v[i].second < v[i + 1].first) dp[i][2] = dp[i][0] + 1;
      ans = maxx(dp[i][0], dp[i][1], dp[i][2]);
    }
    ans = max(ans, 1ll);
    cout << ans << "\n";
  }
  return 0;
}
