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

int main() {
	int n;
	cin >> n;
	vector<pair<int, int>> a(n);

	for (int i = 0; i < n; i ++) {

		cin >> a[i].first >> a[i].second;
	}

	sort(a.begin(), a.end());

	int ans = 1;
	int cnt = a[0].second;

	for (int i = 0; i < n; i ++) {

		if (a[i].first >= cnt) {
			ans ++;
			cnt = a[i].second;
		}
	}

	cout << ans << endl;
	return 0;
}