#include <fstream.h>

int main()
{unsigned int n,i,j,a,b;int nr;
ifstream f("fractii.in");
ofstream g("fractii.out");
f>>n;nr=0;
for(i=1;i<n-1;i++)
   for (j=i+1;j<=n;j++)
       {a=i;b=j;
		while (a!=b) {if (a>b) a=a-b;else b=b-a;}
        if (a==1) nr++;}
g<<nr*2+3;
return 0;}