#include <fstream.h>
unsigned int n, x, y, i, nr=0;
int main()
{
ifstream f("patrate3.in");
f>>n;
for(i=1; i<=n; i++)
   {f>>x;
    f>>y;
   }
ofstream g("patrate3.out");
g<<nr;
f.close();
g.close();
return 0;
}