#include<bits/stdc++.h>
using namespace std;struct r{int l,r;}a[1000001];bool cmp(r a,r b){return a.r<b.r;}int main(){int n;cin>>n;for(int i=1;i<=n;i++) cin>>a[i].l>>a[i].r;sort(a+1,a+n+1,cmp);int f=a[1].r,c=1;for(int i=2;i<=n;i++){if(a[i].l>=f){f=a[i].r;c++;}} cout<<c;return 0;}