#include "bits/stdc++.h"
// @JASPER'S BOILERPLATE
using namespace std;
using ll = long long;
#define FOR(i, a, b) for(int i = a; i <= b; i++)
#define FORD(i, a, b) for(int i = a; i >= b; i--)
#define REP(i, b) for(int i = 0; i < b; i++)
#define PER(i, b) for(int i = b - 1; i >= 0; i--)
#define fi first
#define se second
#ifdef JASPER2
#include "debug.h"
#else
#define debug(...) 166
#endif
using pii = pair < int, int >;
const int INF = 1e9;
const int MOD = 1e9 + 7;
const int N = 1e2 + 5;
int n;
void run_case() {
cin >> n;
vector <pair <int, int>> events(n);
for (int i = 0; i < n; ++i) {
cin >> events[i].fi >> events[i].se;
}
// Sort theo ket thuc
sort(events.begin(), events.end(), [] (pii x, pii y) {
return x.se < y.se;
});
int cnt = 1;
int end_time = events[0].se;
for (int i = 1; i < n; ++i) {
if (events[i].fi > end_time) {
end_time = events[i].se;
++cnt;
}
}
cout << cnt << "\n";
}
signed main() {
cin.tie(0) -> sync_with_stdio(0);
#ifdef JASPER2
freopen("in1", "r", stdin);
#endif
int Test = 1;
//cin >> Test;
for (int test = 1; test <= Test; test++){
run_case();
}
}