#include <bits/stdc++.h>
using namespace std;
const int maxn = 200000 + 10;
pair<int, int> A[maxn];
int s[maxn];
int ans[maxn];
int main() {
  int n;
  cin >> n;
  for (int i = 1; i <= n; i++) {
    cin >> A[i].first;
    ;
    cin >> A[i].second;
  }
  sort(A + 1, A + n + 1);
  for (int i = 1; i <= n; i++) s[i] = 2 * 1000 * 1000 * 1000 + 1;
  ans[1] = 1;
  s[1] = A[1].first + A[1].second;
  for (int i = 2; i <= n; i++) {
    int l = 0, r = n + 1, mid;
    while (r - l != 1) {
      mid = (r + l) / 2;
      if (s[mid] <= A[i].first - A[i].second)
        l = mid;
      else
        r = mid;
    }
    ans[i] = l + 1;
    s[l + 1] = min(s[l + 1], A[i].first + A[i].second);
  }
  int Ans = 0;
  for (int i = 1; i <= n; i++) Ans = max(Ans, ans[i]);
  cout << Ans;
}
