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;
template <typename T>
T modpow(T base, T exp) {
  T result = 1;
  while (exp > 0) {
    if (exp & 1) result = (result * base);
    base = (base * base);
    exp >>= 1;
  }
  return result;
}
pair<int, int> p[500005];
bool comp(const pair<int, int> &p1, const pair<int, int> &p2) {
  return p1.second < p2.second;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  {
    int n;
    cin >> n;
    for (int i = 0; i < n; i++) {
      int l, r;
      cin >> l >> r;
      p[i] = make_pair(l, r);
    }
    sort(p, p + n, comp);
    int ct = 1;
    int curr = p[0].second;
    for (int i = 1; i < n; i++) {
      if (p[i].first > curr) {
        ct++;
        curr = p[i].second;
      }
    }
    cout << ct << '\n';
  }
  return 0;
}
