#include<iostream>

 #include<cstdio>

 #include<algorithm>

 #include<cstring>

 #include<cmath>

 #include<set>

 #include<vector>

 #include<stack>

 #include<queue>

 #include<map>

 using namespace std;

 #define ll long long

 #define se second

 #define fi first

 const int INF= 0x3f3f3f3f;

 const int N=1e6+;

 int n;

 struct note

 {

     int a;

     int b;

 }p[N];

 bool cmp(note x,note y)

 {

     return (x.b<y.b || x.b==y.b&&x.a>y.a);//按b小的排，相等时按a大的排

 }

 int main()

 {

     scanf("%d",&n);

     for(int i=;i<=n;i++) scanf("%d %d",&p[i].a,&p[i].b);

     sort(p+,p++n,cmp);

     int cnt=,u=p[].b;

     for(int i=;i<=n;i++)

     {

         if(p[i].a>= u)

             cnt++, u=p[i].b;

     }

     cout<<cnt;

 }