#include <bits/stdc++.h>
#define ti tuple<int, int, int>
using namespace std;
int n, l[200010], r[200010], mx, val, ans;
priority_queue<ti, vector<ti>, greater<ti>> pq;
struct st {
vector<int> seg;
void init() {
seg.assign(1200000, 0);
}
void update(int l, int r, int idx, int val, int node) {
if(l == r) {
seg[node] = max(seg[node], val);
return;
}
int mid = (l+r)/2;
if(idx <= mid) update(l, mid, idx, val, node*2);
else update(mid+1, r, idx, val, node*2+1);
seg[node] = max(seg[node*2], seg[node*2+1]);
}
int query(int l, int r, int ql, int qr, int node) {
if(ql > r || qr < l) return -1;
if(l >= ql && r <= qr) return seg[node];
int mid = (l+r)/2;
return max(query(l, mid, ql, qr, node*2), query(mid+1, r, ql, qr, node*2+1));
}
};
int main() {
cin.tie(0)->sync_with_stdio(0);
st seg;
seg.init();
cin >> n;
for(int i=1; i<=n; i++) {
while(pq.size() && get<0>(pq.top()) <= i) {
seg.update(1, n, get<1>(pq.top()), get<2>(pq.top()), 1);
pq.pop();
}
cin >> l[i] >> r[i];
if(i-l[i]-1 > 0) mx = seg.query(1, n, 1, i-l[i]-1, 1);
else mx = 0;
pq.push({i+r[i]+1, i, mx+1});
}
while(pq.size()) {
seg.update(1, n, get<1>(pq.top()), get<2>(pq.top()), 1);
pq.pop();
}
cout << seg.query(1, n, 1, n, 1);
}
