#include <stdio.h>
#include <fstream.h>
#include <math.h>
FILE *pf;
long nr;
long cmmdc(long x,long y);
long cmmdc(long x,long y)
{long r;
 do
 {
 r=x%y;
 x=y;
 y=r; }
 while(r);
 if (x==1) return 1;else return 0;
}
long  n;
main(void)
{pf=fopen("fractii.in","r");
long i,j;
fscanf(pf,"%ld",&n);
 nr=2*n-1;
for(i=2;i<=n;i++)
for (j=i+1;j<=n;j++)
if (cmmdc(i,j))nr+=2;
pf=fopen("fractii.out","w");
fprintf(pf,"%ld",nr);
fclose(pf);
return 0;
}