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;
const int Max = 5e5 + 10;
const int MOD = 1e9 + 7;
struct tt {
  int start, finish;
} arr[Max];
bool comp(tt a, tt b) {
  if (a.finish == b.finish) return b.start < a.start;
  return b.finish > a.finish;
}
int main() {
  int n, l, r;
  while (cin >> n) {
    for (int i = 0; i < n; i++) {
      cin >> l >> r;
      arr[i].start = l;
      arr[i].finish = r;
    }
    sort(arr, arr + n, comp);
    int work = arr[0].finish, ans = 1;
    for (int i = 1; i < n; i++) {
      if (arr[i].start > work) {
        work = arr[i].finish;
        ans++;
      }
    }
    cout << ans << endl;
  }
}
