A restaurant received n orders for the rental. Each rental order reserve the restaurant for a continuous period of time, the i-th order is characterized by two time values — the start time li and the finish time ri (li ≤ ri).

Restaurant management can accept and reject orders. What is the maximal number of orders the restaurant can accept?

No two accepted orders can intersect, i.e. they can't share even a moment of time. If one order ends in the moment other starts, they can't be accepted both.

Input

The first line contains integer number n (1 ≤ n ≤ 5·105) — number of orders. The following n lines contain integer values li and ri each (1 ≤ li ≤ ri ≤ 109).

Output

Print the maximal number of orders that can be accepted.

Examples

Input

2
7 11
4 7


Output

1


Input

5
1 2
2 3
3 4
4 5
5 6


Output

3


Input

6
4 8
1 5
4 7
2 5
1 3
6 8


Output

2
#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  int n;
  cin >> n;
  vector<pair<int, int>> vp(n);
  for (int i = 0; i < n; i++) cin >> vp[i].first >> vp[i].second;
  sort(vp.begin(), vp.end());
  long long res = 1;
  pair<int, int> pa = {vp[0].first, vp[0].second};
  for (int i = 0; i < n; i++) {
    if (vp[i].first > pa.second)
      pa = {vp[i].first, vp[i].second}, res++;
    else if (vp[i].second < pa.second)
      pa = {vp[i].first, vp[i].second};
  }
  cout << res << endl;
  return 0;
}
