[1931번] 회의실배정

#include 
#include 

using namespace std;

int N; 
pair P[100000];
int ans = 1;

int main() {
	cin >> N;
	for (int i = 0; i < N; i++) {
		cin >> P[i].second >> P[i].first;
	}
	sort(P, P + N);
	int end = P[0].first;
	for (int i = 1; i < N; i++) {
		if (P[i].second >= end) {
			end = P[i].first;
			ans++;
		}
	}
	cout << ans;
	return 0;
}