#include <bits/stdc++.h>
using namespace std;
#define all(v) (v).begin(),(v).end()
#define pb(a) push_back(a)
#define rep(i, n) for(int i=0;i<n;i++)
#define foa(e, v) for(auto& e : v)
using ll = long long;
const ll MOD7 = 1000000007, MOD998 = 998244353, INF = (1LL << 60);
#define dout(a) cout<<fixed<<setprecision(10)<<a<<endl;

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    ll n;
    cin >> n;
    vector<ll> a(n), b(n);
    vector<pair<ll, ll>> v;
    rep(i, n) {
        cin >> a[i] >> b[i];
        v.push_back({a[i], b[i]});
    }
    sort(all(v));
    multiset<ll> ms;
    foa(e, v) ms.insert(e.first);
    ll ans = 0;
    for(auto [x, y] : v) {
        auto itr = ms.lower_bound(y);
        if(itr == ms.end()) ans ++;
        else ms.erase(itr);
    }
    cout << ans - 1<< endl;
    return 0;
}