#include <bits/stdc++.h>
using namespace std;
struct Node {
int mx = 0;
Node *l, *r;
Node(int val) : mx(val), l(nullptr), r(nullptr) {}
Node(Node *l, Node *r) : mx(0), l(l), r(r) {
if(l) mx = max(mx, l->mx);
if(r) mx = max(mx, r->mx);
}
};
Node *build(int tl, int tr) {
if(tl == tr) return new Node(0);
int tm = (tl + tr) / 2;
return new Node(build(tl, tm), build(tm+1, tr));
}
Node* update(Node *u, int tl, int tr, int p, int v) {
if(tl == tr) return new Node(max(u->mx, v));
int tm = (tl + tr) / 2;
if(p <= tm) return new Node(update(u->l, tl, tm, p, v), u->r);
return new Node(u->l, update(u->r, tm+1, tr, p, v));
}
int query(Node *u, int tl, int tr, int l, int r) {
if(tl > tr || l > tr || tl > r) return 0;
if(l <= tl && tr <= r) return u->mx;
int tm = (tl + tr) / 2;
return max(query(u->l, tl, tm, l, r), query(u->r, tm+1, tr, l, r));
}
signed main() {
int n;
cin >> n;
vector<int> L(n+1), R(n+1), dp(n+1, 1);
for(int i=1; i<=n; i++) cin >> L[i] >> R[i];
vector<Node*> roots;
roots.push_back(build(1, 2*n));
roots.push_back(update(roots[0], 1, 2*n, 1 + R[1], 1));
for(int i=2; i<=n; i++) {
if(i - L[i] - 1 >= 1) dp[i] = query(roots[i-L[i]-1], 1, 2*n, 1, i-1) + 1;
roots.push_back(update(roots.back(), 1, 2*n, i + R[i], dp[i]));
}
cout << *max_element(dp.begin(), dp.end()) << '\n';
return 0;
}
