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;
struct t {
  int s, e;
};
bool comp(t a, t b) { return a.e < b.e; }
int main() {
  int n;
  cin >> n;
  t task[n + 1];
  for (int i = 0; i < n; i++) cin >> task[i].s >> task[i].e;
  sort(task, task + n, comp);
  int temp = task[0].e, c = 1;
  for (int i = 1; i < n; i++) {
    if (task[i].s > temp) {
      c++;
      temp = task[i].e;
    }
  }
  cout << c;
  return 0;
}
