#include <bits/stdc++.h>
using namespace std;
#ifndef ONLINE_JUDGE
#include "debug.h"
#else
#define debug(...) 417
#endif
using i64 = int64_t;
using u32 = uint32_t;
using u64 = uint64_t;
using f64 = double_t;
using i128 = __int128_t;

int main() {
  cin.tie(nullptr)->sync_with_stdio(false);
  cout << fixed << setprecision(20);
  int n;
  cin >> n;
  vector<pair<int, int>> p(n);
  for (auto& [l, r] : p) { cin >> l >> r; }
  int ans = 0;
  while (not p.empty()) {
    ans += 1;
    int x = p.back().second;
    while (not p.empty() and x >= p.back().first) {
      x = min(x, p.back().second);
      p.pop_back();
    }
  }
  cout << ans << "\n";
}