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;
struct S {
  long long sta;
  long long end;
};
bool cmp(S a, S b) {
  if (a.end == b.end) {
    return a.sta < b.sta;
  } else {
    return a.end < b.end;
  }
}
int main() {
  struct S s[500100] = {};
  long long n, i, j, cnt = 0;
  while (~scanf("%lld", &n)) {
    memset(s, 0, sizeof(s));
    for (i = 0; i < n; i++) {
      scanf("%lld%lld", &s[i].sta, &s[i].end);
    }
    sort(s, s + n, cmp);
    for (j = 0, i = 1; i < n; i++) {
      if (s[j].end < s[i].sta) {
        cnt++;
        j = i;
      }
    }
    printf("%lld\n", cnt + 1);
    cnt = 0;
  }
}
