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;
bool cmp(const pair<long long, long long>& p1,
         const pair<long long, long long>& p2) {
  if (p1.second == p2.second) {
    return p1.first < p2.first;
  }
  return p1.second < p2.second;
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long n, q, i, j, x, y, flag = 0, flag1 = 0, sum = 0, p, maxi = INT_MIN,
                              k, a, b, index;
  string s1 = "", s2 = "";
  cin >> n;
  vector<pair<long long, long long> > v;
  v.clear();
  for (i = 0; i < n; i++) {
    cin >> x >> y;
    v.push_back(make_pair(x, y));
  }
  sort(v.begin(), v.end(), cmp);
  for (i = 0; i < v.size(); i++) {
    sum++;
    y = v[i].second;
    while (i < v.size() && v[i].first <= y) {
      i++;
    }
    if (i >= n) {
      break;
    }
    i--;
  }
  maxi = max(sum, maxi);
  cout << maxi;
}
