#include <bits/stdc++.h>
#include <experimental/random>
#include <random>
//#include <ext/pb_ds/assoc_container.hpp>
//using namespace __gnu_pbds;
using namespace std;
using ld = long double;
using ll = long long;
const ll INF = 1e18, MOD = 1e9 + 7;
void solve();
signed main() {
#ifdef LOCAL
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#endif
ios::sync_with_stdio(false);
cin.tie(0);
int q = 1;
//cin >> q;
while (q--) {
solve();
}
}
struct seg_tree {
vector<pair<ll, ll>> tree;
void build(ll v, ll l, ll r, vector<ll>& a) {
if (r - l == 1) {
tree[v] = {a[l], l};
return;
}
ll m = (l + r) / 2;
build(2 * v, l, m, a);
build(2 * v + 1, m, r, a);
tree[v] = min(tree[2 * v], tree[2 * v + 1]);
}
void change(ll v, ll vl, ll vr, ll pos) {
if (vr - vl == 1) {
tree[v].first = INF;
return;
}
ll m = (vl + vr) / 2;
if (pos < m) {
change(2 * v, vl, m, pos);
} else {
change(2 * v + 1, m, vr, pos);
}
tree[v] = min(tree[2 * v], tree[2 * v + 1]);
}
pair<ll, ll> get(ll v, ll vl, ll vr, ll l, ll r) {
if (vl >= r || vr <= l) {
return {INF, INF};
}
if (vl >= l && vr <= r) {
return tree[v];
}
ll m = (vl + vr) / 2;
return min(get(2 * v, vl, m, l, r), get(2 * v + 1, m, vr, l, r));
}
};
void solve() {
ll n; cin >> n;
vector<pair<ll, ll>> a(n);
for (int i = 0; i < n; i++) {
cin >> a[i].first >> a[i].second;
}
sort(a.begin(), a.end());
set<pair<ll, ll>> hv;
vector<ll> fir(n), sec(n);
for (int i = 0; i < n; i++) {
hv.insert({a[i].second, i});
fir[i] = a[i].second - a[i].first;
sec[i] = a[i].second + a[i].first;
}
seg_tree t1, t2;
t1.tree.resize(4 * n), t2.tree.resize(4 * n);
t1.build(1, 0, n, fir);
t2.build(1, 0, n, sec);
queue<ll> bfs;
ll ans = 0;
while (!hv.empty()) {
if (bfs.empty()) {
bfs.push(hv.rbegin()->second);
t1.change(1, 0, n, bfs.back());
t2.change(1, 0, n, bfs.back());
hv.erase(--hv.end());
ans++;
}
ll i = bfs.front();
bfs.pop();
while (true) {
pair<ll, ll> cur = t1.get(1, 0, n, 0, i);
if (cur.first > fir[i]) break;
bfs.push(cur.second);
t1.change(1, 0, n, cur.second);
t2.change(1, 0, n, cur.second);
hv.erase({a[cur.second].second, cur.second});
}
while (true) {
pair<ll, ll> cur = t2.get(1, 0, n, i + 1, n);
if (cur.first > sec[i]) break;
bfs.push(cur.second);
t1.change(1, 0, n, cur.second);
t2.change(1, 0, n, cur.second);
hv.erase({a[cur.second].second, cur.second});
}
}
cout << ans;
}
