#include<bits/stdc++.h>
using namespace std;

int main(){
	int N;
	cin >> N;
	vector<pair<int, int>> p(N);
	for (int i = 0; i < N; i++) cin >> p[i].first >> p[i].second;
	sort(p.begin(), p.end(), [&](pair<int, int> l, pair<int,int> r){
		return l.second > r.second;
	});
	set<pair<int, int>> s;
	s.insert({1 << 30, -1});
	int ans = N - 1;
	for (int i = 0; i < N;i++){
		auto tmp = (*s.lower_bound({p[i].second, -1}));
		if (tmp.second != -1){
			s.erase(tmp);
			ans--;
		}
		s.insert({p[i].first,  i});
	}
	cout << ans << "\n";
}