#include<bits/stdc++.h>
using namespace std;
struct node{
    int begin,end;
}m[101];
bool cmp(node x,node y)
{
    return x.end<y.end;
}
int n,nowend,ans;
int main(){
    cin>>n;
    for(int i=1;i<=n;i++)
    {
        cin>>m[i].begin>>m[i].end;
    }
    sort(m+1,m+1+n,cmp);
    nowend=m[1].end;
    for(int i=2;i<=n;i++)
    {
        if(m[i].begin>=nowend){
            ans++;
            nowend=m[i].end;
        }
    }
    cout<<ans+1;
}
/**************************************************************
	Problem: 1372
	User: hongyipin
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2076 kb
****************************************************************/