#include <cstdio>
#include <cstring>
#include <iostream>
#include <string>
#include <cmath>
#include <bitset>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <deque>
#include <algorithm>
#include <complex>
#include <unordered_map>
#include <unordered_set>
#include <random>
#include <cassert>
using namespace std;
typedef long long int ll;
typedef pair<int, int> P;
random_device rnd;
mt19937 mt(rnd());
uniform_real_distribution<> rnd1(0, 1.0);
struct node_t{
	int val;
	node_t *lch;
	node_t *rch;
	double pri;
	int cnt;
	int lazy_val;
	bool lazy;
	node_t() {}
	node_t(int v, double p):val(v), pri(p), cnt(1), lazy_val(0), lazy(false), lch(nullptr), rch(nullptr){}
 
};

int count(node_t *t){
	return !t ? 0 : t->cnt;
}

void push(node_t *t){
	if(!t) return;
	if(t->lazy){
		t->val+=t->lazy_val;
		if(t->lch){
			t->lch->lazy=true;
			t->lch->lazy_val+=t->lazy_val;
		}
		if(t->rch){
			t->rch->lazy=true;
			t->rch->lazy_val+=t->lazy_val;
		}
		t->lazy_val=0;
		t->lazy=false;
	}
}

node_t *update(node_t *t){
	push(t);
	push(t->lch);
	push(t->rch);
	t->cnt=count(t->lch)+count(t->rch)+1;
	return t;
}

node_t *merge(node_t *l, node_t *r){
	if(!l || !r) return !l ? r : l;
	update(l); update(r);
	if(l->pri > r->pri){
		l->rch=merge(l->rch, r);
		return update(l);
	}else{
		r->lch=merge(l, r->lch);
		return update(r);
	}
}

pair<node_t*, node_t*> split(node_t *t, int v){ //[0, v), [v, inf)
	if(!t) return make_pair(nullptr, nullptr);
	update(t);
	if(v <= t->val){
		pair<node_t*, node_t*> s=split(t->lch, v);
		t->lch=s.second;
		return make_pair(s.first, update(t));
	}else{
		pair<node_t*, node_t*> s=split(t->rch, v);
		t->rch=s.first;
		return make_pair(update(t), s.second);
	}
}

pair<node_t*, node_t*> split2(node_t *t, int k){ //[0, k), [k,n)
	if(!t) return make_pair(nullptr, nullptr);
	update(t);
	if(k <= count(t->lch)){
		pair<node_t*, node_t*> s=split2(t->lch, k);
		t->lch=s.second;
		return make_pair(s.first, update(t));
	}else{
		pair<node_t*, node_t*> s=split2(t->rch, k-1-count(t->lch));
		t->rch=s.first;
		return make_pair(update(t), s.second);
	}
}

node_t *query(node_t *t, int l, int r){
	pair<node_t*, node_t*> s=split(t, l);
	pair<node_t*, node_t*> s2=split(s.second, r);
	if(s2.first){
		s2.first->lazy=true;
		s2.first->lazy_val=1;
	}
	pair<node_t*, node_t*> s3=split2(s2.second, 1);
	return merge(s.first, merge(new node_t(l, rnd1(mt)), merge(s2.first, s3.second)));
}

int main()
{
	int n;
	cin>>n;
	node_t *s=nullptr;
	for(int i=0; i<n; i++){
		int l, r;
		cin>>l>>r;
		s=query(s, l, r);
	}
	cout<<count(s)<<endl;
	return 0;
}