#include<stdio.h>
FILE *f1,*f2;
int main()
{long int n,a,b,nr=1,x,y;
f1=fopen("fractii.in","r");
fscanf(f1,"%li",&n);
fclose(f1);
nr=((n-2)/2+(n-2)%2)*2+(2*n-1);
for(a=3;a<=n-1;a++)
for(b=a+1;b<=n;b++)
{x=a;
 y=b;
while(x!=y)

if(x>y) x-=y;
else y-=x;
if(x==1) nr+=2;}
f2=fopen("fractii.out","w");
fprintf(f2,"%li\n",nr);
fclose(f2);
return 0;
}