#include<bits/stdc++.h>
using namespace std;

#define NAME ""
#define ll long long
#define pii pair < int , int >
#define fi first
#define se second
#define FOR(i, a, b) for (int i = (a), _b = (b); i <= _b; i ++)
#define FORD(i, a, b) for (int i = (a), _b = (b); i >= _b; i --)
#define REP(i, n) for (int i = 0, _n = (n); i < _n; i ++)
#define bit(x, i) (((x) >> (i)) & 1ll)
#define mask(x) (1ll << (x))
#define mem(f, x) memset(f, x, sizeof(f))
#define sz(x) (int32_t) (x.size())

signed main() {
  for(string s: {NAME, ""}) {
    if (fopen((s + ".inp").c_str(), "r")) {
      freopen((s + ".inp").c_str(), "r", stdin);
      freopen((s + ".out").c_str(), "w", stdout);
      break;
    }
  }
  cin.tie(0)->sync_with_stdio(0);

  int n;
  cin >> n;

  set < pii > s;

  FOR(i, 1, n) {
    int X, E;
    cin >> X >> E;

    int l = X - E, r = X + E;

    set < pii > :: iterator it = s.lower_bound({l, 0});
    while (it != s.end()) {
      if (it -> se > r) {
        break;
      }

      it = next(it);
      s.erase(prev(it));
    }

    it = s.upper_bound({l, (int)1e9 + 1});
    if (it == s.begin() || prev(it) -> se < r) {
      s.insert({l, r});
    }

//    for (auto x: s) {
//      cout << x.fi << " " << x.se << "\n";
//    }
//    cout << "\n";
  }

  cout << sz(s);

  return 0;
}