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;
class ProblemBRestaurant {
 public:
  static bool cmp(pair<int, int> a, pair<int, int> b) {
    if (a.second == b.second) return a.first < b.first;
    return a.second < b.second;
  }
  void solve(std::istream& in, std::ostream& out) {
    int n;
    in >> n;
    vector<pair<int, int>> arr;
    for (int i = 0; i < n; ++i) {
      int l, r;
      in >> l >> r;
      arr.emplace_back(l, r);
    }
    sort(arr.begin(), arr.end(), cmp);
    int r = arr[0].second, res = 1;
    for (int i = 1; i < n; ++i) {
      if (arr[i].first > r) ++res, r = arr[i].second;
    }
    out << res;
  }
};
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  ProblemBRestaurant solver;
  std::istream& in(std::cin);
  std::ostream& out(std::cout);
  solver.solve(in, out);
  return 0;
}
