#include<stdio.h>
int n,p,q,c[1000000];
bool ok=false;
void ciur()
{
	int j=0,i=0;
	 for(i=2;i<=n;++i)   
        if(!c[i])   
            for(j=i*i;j<=n+1;j+=i)   
                c[j]=true;  
}
void cautare()
{
	for(int i=0;i<=n && ok!=true;++i)
	{
		if(p==c[i] || q==c[i] || p==c[i] && q==c[i])
			ok=true;
		else ok=false;
	}
}
int main()
{
	int nrfractii=0;
	freopen("fractii.in","r",stdin);
	freopen("fractii.out","w",stdout);
	scanf("%d",&n);
	for(p=1;p<=n;++p)
		for(q=1;q<=n;++q)
		{
			ciur();
			cautare();
			if(ok==true)
				++nrfractii;
			ok=false;
		}
	printf("%d",nrfractii);
	return 0;
}