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 data {
  long long a, b;
};
bool cmp(data x, data y) { return x.b < y.b; }
long long int n, ans, k, m, i;
data d;
vector<data> v;
int main() {
  cin >> n;
  for (i = 0; i < n; i++) {
    cin >> d.a >> d.b;
    v.push_back(d);
  }
  sort(v.begin(), v.end(), cmp);
  ans = 1;
  for (i = 1; i < n; i++) {
    if (v[i].a > v[i - 1].b)
      ans++;
    else {
      v[i].a = v[i - 1].a;
      v[i].b = v[i - 1].b;
    }
  }
  cout << ans << "\n";
  return 0;
}
