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() {
  int n;
  cin >> n;
  vector<pair<int, int> > nums;
  pair<int, int> temp;
  while (n-- > 0) {
    cin >> temp.second >> temp.first;
    nums.push_back(temp);
  }
  sort(nums.begin(), nums.end());
  int count = 1;
  n = 1;
  int prev = nums[0].first;
  while (n < nums.size()) {
    if (nums[n].second > prev) {
      prev = nums[n].first;
      count++;
    }
    n++;
  }
  cout << count << endl;
}
