#include <bits/stdc++.h>
using namespace std;
const int N = 2e5;
int pref[N];
int main() {
  int n;
  cin >> n;
  vector<pair<int, int> > v;
  for (int i = 0; i < n; i++) {
    int x, w, l, r;
    cin >> x >> w;
    l = x - w;
    r = x + w;
    v.push_back(make_pair(r, l));
  }
  sort(v.begin(), v.end());
  for (int i = 0; i < n; i++) {
    int l = 0, r = i;
    while (r - l > 1) {
      int m = (l + r) / 2;
      if (v[m].first <= v[i].second)
        l = m;
      else
        r = m;
    }
    pref[i] =
        max(i ? pref[i - 1] : 0, v[l].first <= v[i].second ? pref[l] + 1 : 1);
  }
  cout << pref[n - 1] << endl;
  return 0;
}
