#include <bits/stdc++.h>
using namespace std;
long long int dp[200011];
int main() {
  long long int n;
  cin >> n;
  long long int x, w;
  vector<pair<long long int, pair<long long int, long long int> > > v;
  long long int ans = 0;
  for (int i = 1; i <= n; i++) {
    scanf("%lld", &x);
    scanf("%lld", &w);
    v.push_back({x + w, {x, w}});
  }
  sort(v.begin(), v.end());
  dp[0] = 1;
  ans = 1;
  long long int lo, hi, mid, r;
  for (int i = 1; i < n; i++) {
    r = v[i].second.first - v[i].second.second;
    if (i <= 2) {
      for (int j = 0; j < i; j++) {
        if (v[j].first <= r) dp[i] = max(dp[i], dp[j]);
      }
      dp[i]++;
    } else {
      lo = 0;
      hi = i;
      while (hi - lo > 1) {
        mid = (hi + lo) / 2;
        if (v[mid].first <= r) {
          lo = mid;
        } else {
          hi = mid;
        }
      }
      if (v[lo].first <= r)
        dp[i] = dp[lo] + 1;
      else
        dp[i] = 1;
    }
    dp[i] = max(dp[i], dp[i - 1]);
  }
  cout << dp[n - 1];
}
