#include <iostream>
#include <vector>
#include <algorithm>
 
using namespace std;
 
int n;
int ans;
 
vector<vector<int>> v;
 
void solve() {
 
	int start = v[n-1][0];
	ans ++;
 
	for(int i=n-2; i>=0; i--) {
		if(v[i][1]<=start) {
			ans++;
			start = v[i][0];
		}
	}
 
}
 
int main() {
 
	cin >> n;
	int start, end;
 
	for(int i=0; i<n; i++) {
		cin >> start >> end;
 
		vector<int> temp;
		temp.push_back(start);
		temp.push_back(end);
 
		v.push_back(temp);
	}
 
	sort(v.begin(), v.end());
 
	solve();
 
	cout << ans;
 
	return 0;
}

I2luY2x1ZGUgPGlvc3RyZWFtPgojaW5jbHVkZSA8dmVjdG9yPgojaW5jbHVkZSA8YWxnb3JpdGhtPgoKdXNpbmcgbmFtZXNwYWNlIHN0ZDsKCmludCBuOwppbnQgYW5zOwoKdmVjdG9yPHZlY3RvcjxpbnQ+PiB2OwoKdm9pZCBzb2x2ZSgpIHsKCQoJaW50IHN0YXJ0ID0gdltuLTFdWzBdOwoJYW5zICsrOwoJCglmb3IoaW50IGk9bi0yOyBpPj0wOyBpLS0pIHsKCQlpZih2W2ldWzFdPD1zdGFydCkgewoJCQlhbnMrKzsKCQkJc3RhcnQgPSB2W2ldWzBdOwoJCX0KCX0KCQp9CgppbnQgbWFpbigpIHsKCQoJY2luID4+IG47CglpbnQgc3RhcnQsIGVuZDsKCQoJZm9yKGludCBpPTA7IGk8bjsgaSsrKSB7CgkJY2luID4+IHN0YXJ0ID4+IGVuZDsKCQkKCQl2ZWN0b3I8aW50PiB0ZW1wOwoJCXRlbXAucHVzaF9iYWNrKHN0YXJ0KTsKCQl0ZW1wLnB1c2hfYmFjayhlbmQpOwoJCQoJCXYucHVzaF9iYWNrKHRlbXApOwoJfQoJCglzb3J0KHYuYmVnaW4oKSwgdi5lbmQoKSk7CgkKCXNvbHZlKCk7CgkKCWNvdXQgPDwgYW5zOwoJCglyZXR1cm4gMDsKfQ==

MTMKNyAxMDEKMTIxIDIxOQoyMTYgMzMwCjEgMzM2CjcyIDM0NAoxNTYgMzY5CjcgNDEyCjQyIDQyNgoyMjkgNDUxCjYzIDQ1MwoxOTcgNDc2CjIxNCA1NDUKNTY4IDU3Nw==

13
7 101
121 219
216 330
1 336
72 344
156 369
7 412
42 426
229 451
63 453
197 476
214 545
568 577