#include <stdio.h>
#include <algorithm>
using namespace std;
struct map {
    int no, go, h;
} a[1000005];
bool s[1000005];
long long int n, ans, p = -1;
bool cmp(map a, map b) { return a.go < b.go; }
int main() {
    scanf("%lld", &n);
    for (int i = 1; i <= n; ++i) {
        scanf("%lld%lld", &a[i].no, &a[i].go);
    }
    sort(a + 1, a + n + 1, cmp);
    for (int i = 1; i <= n; ++i) {
        if (p <= a[i].no && a[i].end == 0) {
            for (int j = 1; j <= n; ++j) {
                if (s == 0 && a[i].go >= a[j].no)
                    s = 1;
            }
            p = a[i].go;
            ++ans;
        }
    }
    printf("%lld", ans);
    return 0;
}

/sandbox/1/a.cpp: In function 'int main()':
/sandbox/1/a.cpp:18:13: warning: format '%lld' expects argument of type 'long long int*', but argument 2 has type 'int*' [-Wformat=]
   18 |   scanf("%lld%lld",&a[i].no,&a[i].go);
      |          ~~~^      ~~~~~~~~
      |             |      |
      |             |      int*
      |             long long int*
      |          %d
/sandbox/1/a.cpp:18:17: warning: format '%lld' expects argument of type 'long long int*', but argument 3 has type 'int*' [-Wformat=]
   18 |   scanf("%lld%lld",&a[i].no,&a[i].go);
      |              ~~~^           ~~~~~~~~
      |                 |           |
      |                 |           int*
      |                 long long int*
      |              %d
/sandbox/1/a.cpp:23:23: error: 'struct map' has no member named 'end'
   23 |   if(p<=a[i].no&&a[i].end==0)
      |                       ^~~
/sandbox/1/a.cpp:28:6: error: incompatible types in assignment of 'int' to 'bool [1000005]'
   28 |     s=1;
      |     ~^~
/sandbox/1/a.cpp:15:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   15 |  scanf("%lld",&n);
      |  ~~~~~^~~~~~~~~~~
/sandbox/1/a.cpp:18:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   18 |   scanf("%lld%lld",&a[i].no,&a[i].go);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~