#include <stdio.h>
char a[90000][90000];
int main()
{ long long n,i,j,p,q,c=0;
FILE*f=fopen("fractii.in","r");
FILE*g=fopen("fractii.out","w");
fscanf(f,"%lld",&n);
for (q=1;q<=n;q++)
	for (p=1;p<=n;p++)
		if(a[p][q]==0)
			{
			j=2;
			while (p*j<=1600)
				{
				a[p*j][q*j]=1;
				j++;
				}
			c++;
			}
fprintf(g,"%lld",c);
return 0;
}