#include <iostream>
#include <vector>
#include <queue>
#include <array>
using namespace std;
using ai3 = array<int,3>;
struct SegTree {
int base, ql, qr;
vector<int> tree;
SegTree(int N) {
base = 1;
while (base < N) base *= 2;
tree.resize(2*base, 0);
}
void upd(int i, int x) {
i += base;
tree[i] = max(x, tree[i]);
i /= 2;
for (; i > 0; i /= 2) tree[i] = max(tree[2*i], tree[2*i+1]);
}
int __mx(int i, int l, int r) {
if (qr <= l || r <= ql) return 0;
if (ql <= l && r <= qr) return tree[i];
int m = (l+r) / 2;
return max(__mx(2*i, l, m), __mx(2*i+1, m, r));
}
int mx(int l, int r) {
if (r <= l) return 0;
ql = l; qr = r;
return __mx(1, 0, base);
}
};
int main() {
int N; cin >> N;
vector<int> L(N), R(N);
for (int i = 0; i < N; i++) cin >> L[i] >> R[i];
SegTree st(N);
priority_queue<ai3, vector<ai3>, greater<ai3>> pq;
for (int i = 0; i < N; i++) {
int score = st.mx(0, i-L[i]) + 1;
pq.push({i+R[i], i, score});
while (pq.size() && pq.top()[0] <= i) {
auto[_,pos,val] = pq.top();
pq.pop();
st.upd(pos, val);
}
}
int out = st.mx(0,N);
while (pq.size()) {
auto[_,pos,val] = pq.top();
pq.pop();
out = max(out, val);
}
cout << out << endl;
}
