#include <bits/stdc++.h>
using namespace std;
int n;
vector<pair<int, int> > S;
int dp[1000005];
int rek(int pos) {
  if (pos == n) {
    return 0;
  }
  int &ans = dp[pos];
  if (ans != -1) return ans;
  ans = 1;
  ans = max(ans, rek(pos + 1));
  int nex = lower_bound(S.begin(), S.end(), make_pair(S[pos].second + 1, -1)) -
            S.begin();
  ans = max(ans, rek(nex) + 1);
  return ans;
}
int main() {
  scanf("%d", &n);
  for (int i = 0; i < n; i++) {
    int l, r;
    scanf("%d%d", &l, &r);
    S.push_back(make_pair(l, r));
  }
  sort(S.begin(), S.end());
  memset(dp, -1, sizeof(dp));
  printf("%d\n", rek(0));
  return 0;
}
