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 rc {
  int l, r;
};
int n, m, dem, ans;
rc a[500005];
void openfile() {
  freopen("test.inp", "r", stdin);
  freopen("test.out", "w", stdout);
}
void closefile() {
  fclose(stdin);
  fclose(stdout);
}
bool cmp(rc a, rc b) { return ((a.l < b.l) || (a.l == b.l && a.r < b.r)); }
void processing() {
  scanf("%d", &n);
  for (int i = 1; i <= n; i++) scanf("%d%d", &a[i].l, &a[i].r);
  sort(a + 1, a + 1 + n, cmp);
  dem = 0;
  ans = 1;
  m = 0;
  for (int i = 1; i <= n; i++) {
    if (a[i].l > m) {
      m = a[i].r;
      dem++;
    } else {
      m = min(m, a[i].r);
    }
    ans = max(ans, dem);
  }
  printf("%d", ans);
}
int main() {
  processing();
  return 0;
}
