#include<stdio.h>
int main()
{long n,i,m,a,b,j,k,r;
FILE *f=fopen("fractii.in","r");
FILE *g=fopen("fractii.out","w");
fscanf(f,"%ld",&n);
if (n%2==0)k=n*2-2+n/2;
else k=n*2-1+n/2;
for (i=2; i<=n; i++)
		{ if (i%2==0) m=2;
		else m=1;
		for (j=3; j<=n; j=j+m)
			{a=i; b=j; r=a%b; while (r!=0){a=b; b=r; r=a%b;}
							if (b==1) k++;}
		}
fprintf(g,"%ld",k);
 fclose(f);
 fclose(g);
 return 0;  }