#include <iostream.h>
#include <math.h>
#include <fstream.h>
int eprim(int x){
int i;
if(x%2==0)return 0;
for(i=2;i<=x/2;i++)
	if(x%i==0)return 0;
return 1;
}
int main(){
ifstream f("fractii.in");
ofstream g("fractii.out");
int n,i,nr,j,s=1;
f>>n;
for(i=1;i<=n;i++)
	for(j=1;j<=n;j++)
		if(i!=j&&(eprim(i)==1||eprim(j)==1))s++;
g<<s;
f.close();
g.close();
return 0;
}