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>
struct order {
  int begin;
  int last;
};
int cmp(const void *a, const void *b) {
  return (*(order *)a).last - (*(order *)b).last;
}
int main() {
  int n, min, rem, k = 1;
  scanf("%d", &n);
  struct order din[n], cup;
  for (int i = 0; i < n; i++) {
    scanf("%d %d", &din[i].begin, &din[i].last);
  }
  qsort(din, n, sizeof(struct order), cmp);
  rem = din[0].last;
  for (int i = 1; i < n; i++) {
    if (din[i].begin > rem) {
      k++;
      rem = din[i].last;
    }
  }
  printf("%d\n", k);
  return 0;
}
