#include<stdio.h>
int n,s,i,j;
FILE *f,*g;
int cmmdc (int a,int b)
{
while(a!=b)if(a>b)a-=b;else b-=a;
return a;
}

int main ()
{
f=fopen("fractii.in","r");
fscanf(f,"%d",&n);fclose(f);
s=2*n-1;
for(i=2;i<=n-1;i++){
	for(j=i+1;j<=n;j++){if(cmmdc(i,j)==1)s+=2;}}
g=fopen("fractii.out","w");
fprintf(g,"%d",s);
fclose(g);
return 0;
}