#include <bits/stdc++.h>

using namespace std;

#define IL inline
#define vec vector
#define eb emplace_back
#define emp emplace
IL void ckx(int &x, const int &y) { (x < y) && (x = y); }
IL void ckm(int &x, const int &y) { (x > y) && (x = y); }

const int maxN = 5e5 + 7;

int n;

struct seg {
  int l, r;
} a[maxN];

priority_queue<int, vec<int>, greater<int>> A, B;

int main() {

  cin.tie(nullptr) -> sync_with_stdio(false);

  cin >> n;
  for (int i = 1; i <= n; i++)
    cin >> a[i].l >> a[i].r;
  sort(a + 1, a + n + 1, [](const auto &A, const auto &B) {
    return A.l < B.l;
  });
  int ans = 0;
  for (int i = 1; i <= n; i++) {
    if (!A.empty() && A.top() < a[i].l) {
      ans++;
      B.emp(a[i].r);
      A.pop();
    } else if (!B.empty() && B.top() < a[i].r) {
      A.emp(B.top());
      B.pop();
      B.emp(a[i].r);
    } else A.emp(a[i].r);
  }
  cout << ans << '\n';
}