#include <fstream.h>

int main()
{

	ifstream fin("fractii.in");
	ofstream fout("fractii.out");
	int ok[1000], i, j, n, s, ap = 0;

	fin >> n;
	memset (ok,1,sizeof(ok));
	for ( i = 1; i*i <= n; i++ )
		for ( s = 1; s*s <= n; s++ )
			if ( ok[i/s] )
			{
				j = 2;
				while ( (i*j)/(s*j) <= n )
				{
					ok[(i*j)/(s*j)] = 0;
					j++;
				}
			}
		for ( i = 1; i <= n; i++ )
			for ( s = 1; s <= n; s++ )
				if ( ok[i/s] )
					ap++;

	fout << ap;
	fin.close();
	fout.close();



	return 0;
}