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;
pair<long long, long long> ii[5 * 100000];
inline long long in() {
  long long res = 0;
  char c;
  while ((c = getchar()) < '0' || c > '9')
    ;
  while (c >= '0' && c <= '9') res = res * 10 + c - '0', c = getchar();
  return res;
}
int main() {
  int n, sum = 1;
  long long last;
  n = in();
  for (int i = 0; i < n; i++) ii[i].second = in(), ii[i].first = in();
  sort(ii, ii + n);
  last = ii[0].first;
  for (int i = 1; i < n; i++)
    if (ii[i].second > last) last = ii[i].first, sum++;
  printf("%d", sum);
  return 0;
}
