// lowk prob WA
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define FOR(i,N) for(ll i = 0; i < N; i++)
#define all(x) (x).begin(), (x).end()
#define F first
#define S second
signed main() {
cin.tie(0); ios::sync_with_stdio(false);
ll N;
cin >> N;
vector<vector<ll>> order;
FOR(i, N) {
ll l, r;
cin >> l >> r;
order.push_back({min(N-1,i+r), i, max(0ll, i-l)}); // end, i, start
}
sort(all(order));
pair<ll,ll> end = {-1, -1};
ll cnt = 0;
FOR(i, N) {
if (order[i][1] > end.F && order[i][2] > end.S) {
// cout << order[i][2] << ' ' << order[i][1] << ' ' << order[i][0] << ' ' << end.S << ' ' << end.F << endl;
end = {order[i][0], i};
cnt++;
}
}
cout << cnt;
}
