#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int INF = 1e9 + 7;
int N;
vector<int> tree, L, R;
void update(int v, int p, int tl = 0, int tr = N-1, int i = 1) {
if (tl == tr) {tree[i] = v; return ;}
int tm = (tl + tr) / 2;
if (p <= tm) update(v, p, tl, tm, i * 2);
else update(v, p, tm + 1, tr, i * 2 + 1);
tree[i] = max(tree[i * 2], tree[i * 2 + 1]);
}
int query(int l, int r, int tl = 0, int tr = N-1, int i = 1) {
if (l > r) return 0;
if (tl == l && tr == r) return tree[i];
int tm = (tl + tr) / 2;
return max(query(l, min(r, tm), tl, tm, i * 2), query(max(l, tm + 1), r, tm + 1, tr, i * 2 + 1));
}
signed main() {
cin.tie(0); ios::sync_with_stdio(false);
cin >> N;
tree.resize(N*4), L.resize(N), R.resize(N);
for(int i = 0; i < N; i++) {
cin >> L[i] >> R[i];
}
vector<vector<pair<int,int>>> to_upd(N+1);
for(int i = 0; i < N; i++) {
for(auto &[v, p]: to_upd[i]) {
update(v, p);
}
to_upd[min(N, i + R[i] + 1)].push_back({1 + query(0, i - L[i] - 1), i});
}
for(auto &[v, p]: to_upd[N]) {
update(v, p);
}
cout << query(0, N-1);
}
