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;
long long int n;
long long int dp[1000000][2];
vector<pair<long long int, long long int> > a;
bool comp(pair<long long int, long long int> x,
          pair<long long int, long long int> y) {
  return x.second < y.second;
}
int main() {
  cin >> n;
  for (long long int i = 0; i < n; i++) {
    long long int x, y;
    cin >> x >> y;
    a.push_back(make_pair(x, y));
  }
  sort(a.begin(), a.end(), comp);
  long long int ans = 0;
  long long int last = 0;
  for (long long int i = 0; i < n; i++) {
    if (a[i].first > last) {
      ans += 1;
      last = a[i].second;
    }
  }
  cout << ans;
}
