#include <bits/stdc++.h>
using namespace std;
int main(){
cin.tie(0);
ios_base::sync_with_stdio(0);
int n;
cin >> n;
int l[n+1], r[n+1];
int dp[n+2];
for (int i = 0; i <= n + 1; i++){
dp[i] = 0;
}
for (int i = 1; i <= n; i++) cin >> l[i] >> r[i];
priority_queue <pair<int, int>> qe;
pair <int, pair<int, int>> intervals[4*n];
bool leaves[4*n];
queue <pair<int, pair<int, int>>> q;
q.push({0, {1, n}});
while (!q.empty()){
int cur = q.front().first, s = q.front().second.first, e = q.front().second.second;
q.pop();
intervals[cur] = {0, {s, e}};
leaves[cur] = 1;
if (s == e) continue;
leaves[cur] = 0;
q.push({cur * 2 + 1, {s, (s + e) / 2}});
q.push({cur * 2 + 2, {(s + e) / 2 + 1, e}});
}
for (int i = 1; i <= n; i++){
while (!qe.empty() && -qe.top().first <= i){
int s = qe.top().second;
qe.pop();
int k = dp[s];
int cur = 0;
while (!leaves[cur]){
intervals[cur].first = max(intervals[cur].first, k);
if (intervals[cur*2+1].second.second >= s){
cur = cur * 2 + 1;
}
else cur = cur * 2 + 2;
}
intervals[cur].first = max(intervals[cur].first, k);
}
qe.push({-(i + 1 + r[i]), i});
int st = 1, e = i - 1 - l[i];
if (e < 1){
dp[i] = 1;
continue;
}
queue <int> qa;
qa.push(0);
while (!qa.empty()){
int s = qa.front();
qa.pop();
if (intervals[s].second.first > e || intervals[s].second.second < st) continue;
if (intervals[s].second.first >= st && intervals[s].second.second <= e){
dp[i] = max(dp[i], intervals[s].first + 1);
}
qa.push(s*2+1);
qa.push(s*2+2);
}
}
int maxs = 0;
for (int i = 0; i <= n; i++){
maxs = max(maxs, dp[i]);
}
cout << maxs <<endl;
}
