#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using P = pair<ll, ll>;
#define rep(i, a, b) for(ll i = a; i < b; ++i)
#define rrep(i, a, b) for(ll i = a; i >= b; --i)
constexpr ll inf = 4e18;
struct SetupIO {
    SetupIO() {
        ios::sync_with_stdio(0);
        cin.tie(0);
        cout << fixed << setprecision(30);
    }
} setup_io;
int main(void) {
    ll n;
    cin >> n;
    vector<P> r(n);
    rep(i, 0, n) {
        cin >> r[i].first >> r[i].second;
    }
    ranges::sort(r);
    ranges::reverse(r);
    ll ans = n;
    ll cur = inf;
    rep(i, 0, n) {
        if(r[i].second <= cur) {
            ans--;
            cur = r[i].first;
        }
    }
    cout << ans << '\n';
}