#include<stdio.h>

FILE *f=fopen("fractii.in","r"), *g=fopen("fractii.out","w");

int div(int x,int y) {
    if(x==y) return x;
    else {
       if(x>y) return(div(x-y,x));
       else return(div(x,y-x));
    }
}

int n,i,j,x;

int main() {
   fscanf(f,"%d",&n);
   for(i=1;i<=n;i++)
      for(j=1;j<=i;j++)
	 if(div(i,j)==1) x++;
   x*=2; x--;
   fprintf(g,"%d",x);
   fclose(f);
   fclose(g);
   return 0;
}