#include<stdio.h>
#include<math.h>
int cmmdc(int a,int b)
{if (b==1) return 1;
 if (b==0) return a;
 else return cmmdc(b,a%b);
}
void main()
{int x,k,i,j;
FILE *f,*g;
f=fopen("fractii.in","r");
g=fopen("fractii.out","w");
fscanf(f,"%i",&x);
k=0;
for(i=2;i<=x;i++)
{for(j=i+1;j<=x;j++)
{if(cmmdc(i,j)==1)k++;}}
k*=2;
k+=2*x-1;
fprintf(g,"%i",k);
fclose(f);
fclose(g);
}