#include <bits/stdc++.h>
#pragma GCC optimize("-Ofast")
using namespace std;
long long int findgcd(long long int a, long long int b) {
  if (b == 0) return a;
  return findgcd(b, a % b);
}
bool check(long long int n, long long int s) {
  long long int tem = n;
  long long int sum = 0;
  while (tem > 0) {
    sum += tem % 10;
    tem = tem / 10;
  }
  if (abs(n - sum) >= s)
    return true;
  else
    return false;
}
bool cmp(vector<int> a, vector<int> b) {
  if (a[0] == b[0])
    return a[1] < b[1];
  else
    return a[0] < b[0];
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int t;
  t = 1;
  for (int i1 = 0; i1 < t; i1++) {
    int n;
    cin >> n;
    vector<vector<int> > arr(n, vector<int>(2)), arrn;
    for (int i = 0; i < n; i++) cin >> arr[i][0] >> arr[i][1];
    sort(arr.begin(), arr.end(), cmp);
    int mini = arr[0][1];
    int ans = 1;
    for (int i = 1; i < n; i++) {
      if (arr[i][0] > mini) {
        ans++;
        mini = arr[i][1];
      } else
        mini = min(arr[i][1], mini);
    }
    cout << ans;
  }
}
