#include<bits/stdc++.h>
using namespace std;
struct stu{
	int left, right;
}a[2000005];
bool cmp(stu x, stu y){
	return x.right < y.right;
}
int main(){
	int n;
	cin >> n;
	for(int i = 1; i <= n; i++)
		cin >> a[i].left >> a[i].right;
	sort(a+1, a+1+n, cmp);
	int t = a[1].right;
	int sum = 1;
	int j = 1; 
	while(j <= n){
		j++;
		if(t <= a[j].left){
			t = a[j].right;
			sum++;
		}
	} 
	printf("%d", sum);
	return 0;
}