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 int MAXN = 1e6;
const int MAXE = 200500;
const int INF = 0x3f3f3f;
struct node {
  int s, e;
} x[MAXN];
bool cmp(node a, node b) {
  if (a.e == b.e) return a.s > b.s;
  return a.e < b.e;
}
int main() {
  int n;
  while (~scanf("%d", &n)) {
    for (int i = 0; i < n; i++) scanf("%d%d", &x[i].s, &x[i].e);
    sort(x, x + n, cmp);
    int ans = 0, now = 1;
    for (int i = 0; i < n; i++) {
      if (now <= x[i].s) {
        ans++;
        now = x[i].e + 1;
      }
    }
    printf("%d\n", ans);
  }
  return 0;
}
