// #include <bits/allocator.h> // Temp fix for gcc13 global pragma
// #pragma GCC target("avx2,bmi2,popcnt,lzcnt")
// #pragma GCC optimize("O3,unroll-loops")
#include <bits/stdc++.h>
// #include <x86intrin.h>
using namespace std;
#if __cplusplus >= 202002L
using namespace numbers;
#endif
#ifdef LOCAL
	#include "Debug.h"
#else
	#define debug_endl() 42
	#define debug(...) 42
	#define debug2(...) 42
	#define debugbin(...) 42
#endif



int main(){
	cin.tie(0)->sync_with_stdio(0);
	cin.exceptions(ios::badbit | ios::failbit);
	int n;
	cin >> n;
	vector<array<int, 2>> a(n);
	for(auto &[l, r]: a){
		cin >> l >> r;
	}
	ranges::sort(a);
	multiset<pair<int, int>> s;
	for(auto [l, r]: a){
		if(s.empty()){
			s.insert({r, l});
		}
		else{
			auto it = s.lower_bound(pair{l, numeric_limits<int>::max()});
			if(it == s.begin()){
				s.insert({r, l});
			}
			else{
				auto [cr, cl] = *prev(it);
				s.erase(prev(it));
				s.insert({r, cl});
			}
		}
	}
	cout << (int)s.size() - 1 << "\n";
	return 0;
}

/*

*/