#include <bits/stdc++.h>
#define int long long
using namespace std;
const int N=5e5;
map<int,int> mp;
int val[N+1];
//nen x
pair<int,int> p[N+1];
bool took[N+1];
struct event
{
int tme, id;
bool operator < (const event & o) const
{
return tme < o.tme;
}
};
priority_queue<event> pq;
int32_t main()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
int n;
cin >> n;
for(int i=1;i<=n;++i)
{
cin >> p[i].second >> p[i].first;
mp[p[i].second]=0;
}
int tme=0;
for(auto& k : mp)
{
val[++tme] = k.first;
k.second=tme;
}
sort(p+1,p+n+1);
//priority_queue<pair<int,int>>
int cnt=0;
for(int i=n;i>0;--i)
{
p[i].second=mp[p[i].second];
//cout << "SET " << p[i].first << " :\n";
while(!pq.empty() && pq.top().tme>=p[i].first)
{
auto k = pq.top();
pq.pop();
if(took[k.id]==1) continue;
//cout << k.id << " " << k.tme << '\n';
took[k.id]=1;
if(k.id>1 && !took[k.id-1])
{
int tme = k.tme - (val[k.id]-val[k.id-1]);
pq.push({tme,k.id-1});
}
if(k.id<n && !took[k.id+1])
{
int tme = k.tme- (- val[k.id]+val[k.id+1]);
pq.push({tme,k.id+1});
}
}
if(!took[p[i].second])
{
//cout << i << "L";
pq.push({p[i].first,p[i].second});
cnt++;
}
}
cout << cnt;
}
