#include <bits/stdc++.h>
using namespace std;
struct segTree {
vector<int> v;
int sz;
void init (int n) {
sz = 1;
while (sz < n) sz *= 2;
v.assign(2 * sz, 0);
}
void set(int i, int val, int x, int lx, int rx) {
if (rx - lx == 1) {
v[x] = max(v[x], val);
return;
}
int m = (lx + rx) / 2;
if (i < m) set(i, val, 2 * x + 1, lx, m);
else set(i, val, 2 * x + 2, m, rx);
v[x] = max(v[2 * x + 1], v[2 * x + 2]);
}
void set(int i, int val) {
set(i, val, 0, 0, sz);
}
int calc(int l, int r, int x, int lx, int rx) {
if (lx >= l && rx <= r) return v[x];
else if (lx >= r || rx <= l) return 0;
int m = (lx + rx) / 2;
return max(calc(l, r, 2 * x + 1, lx, m), calc(l, r, 2 * x + 2, m, rx));
}
int calc(int l, int r) {
return calc(l, r, 0, 0, sz);
}
};
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
int N; cin >> N;
vector<int> l(N), r(N);
for (int i = 0; i < N; i++) cin >> l[i] >> r[i];
segTree st; st.init(N);
vector<vector<pair<int, int>>> add(N+1);
int ans = 0;
for (int i = 0; i < N; i++) {
for (pair<int, int> pr : add[i]) st.set(pr.first, pr.second);
int mx = st.calc(0, i - l[i]);
ans = max(ans, mx + 1);
add[min(N, i + r[i] + 1)].push_back({i, mx+1});
}
cout << ans << "\n";
}
