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 long long nmax = 500005;
const int mod = 1e9 + 7;
const double inf = 3 * 1e12;
pair<long long, long long> a[nmax];
long long dp[nmax];
int main() {
  long long n;
  cin >> n;
  for (int i = 0; i < n; ++i) {
    cin >> a[i].first >> a[i].second;
  }
  sort(a, a + n);
  dp[0] = 1;
  long long mx = 1;
  int last = 0;
  for (int i = 1; i < n; ++i) {
    if (a[last].second < a[i].first && dp[last] + 1 > dp[i - 1]) {
      dp[i] = dp[last] + 1;
      last = i;
    } else {
      dp[i] = dp[i - 1];
      if (a[last].second > a[i].second) last = i;
    }
    mx = max(dp[i], mx);
  }
  cout << mx << endl;
  return 0;
}
