#include<string.h>
#include<stdio.h>
int i,j; long n,contor=1;
FILE *f,*g;
long cmmdc(long a, long b)
{
while(a!= b)if(a>b)a-=b;else b-=a;
return a;

}
int main()

{f=fopen("numere.in","r");
g=fopen("numere.out","w");
fscanf(f,"%ld\n",&n);
for(i=1;i<n;i++)for(j=i+1;j<=n;j++)if(cmmdc(i,j)==1)contor+=2;
fprintf(g,"%l",contor);
fclose(f);fclose(g);
return 0;}