#include<fstream.h>

unsigned long d,i,n,ok,ciur;
unsigned long PRIM(unsigned long);

main()
{
	ifstream In("ciur.in");
	ofstream Out("ciur.out");
	In>>n;
	In.close();

	for(;i<n;i++)
	{
		if(PRIM(i)) ciur++;
	}
	Out<<ciur<<'\n';
	Out.close();
	return 0;
}

unsigned long PRIM(unsigned long x)
{
	ok=1;
	for(d=2;d<=7;d++)
	  if(x%d==0) ok=0;
	return ok;
}