#include 
#include 
#include 
using namespace std;
 
int main()
{
int n;
int brojac=1;
cin>>n;
vector>v;
for(int i=0; i>a>>b;
v.push_back(make_pair(b, a));
}
sort(v.begin(), v.end());
 
    int nd=v[0].first;
    int start=v[0].second;
 
for(int j=1; j=nd){
     brojac+=1;
     nd=tnd;
     start=tstart;
    }
}
cout<