#include<bits/stdc++.h> using namespace std; struct st{ int begin,end; }; st a[1005]; bool cmp(st x,st y){ return x.end<y.end; } int main(){ freopen("select.in","r",stdin); freopen("select.out","w",stdout); int x; cin>>x; for(int i=1;i<=x;i++){ cin>>a[i].begin>>a[i].end; } sort(a+1,a+x+1,cmp); int sum=1,k=a[1].end; for(int i=2;i<=x;i++){ if(a[i].begin>=k){ sum++; k=a[i].end; } } cout<<sum<<endl; }