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;
pair<int, int> arr[500005];
bool cmp(pair<int, int> a, pair<int, int> b) {
  if (a.first == b.first)
    return a.second < b.second;
  else
    return a.first < b.first;
}
int main() {
  int n;
  cin >> n;
  for (int i = 1; i <= n; i++) {
    cin >> arr[i].first >> arr[i].second;
  }
  sort(arr + 1, arr + 1 + n, cmp);
  int cnt = 1;
  int temp = arr[1].second;
  pair<int, int> last = arr[1];
  for (int i = 2; i <= n; i++) {
    if (arr[i].first > temp) {
      temp = arr[i].second;
      cnt++;
    } else {
      temp = min(temp, arr[i].second);
    }
  }
  cout << cnt;
}
