#include<fstream.h>
ifstream f("fractii.in");
ofstream g("fractii.out");
char a[1000];
long cm(long a,long b)
{while(b)
{long r=a%b; a=b; b=r;}
return a;
}


int main()
{ long n;
f>>n;
 long t=0;
for( long i=3;i<=n;i++)
for( long j=2;j<i;j++)
if(cm(i,j)==1) t++;
g<<1+2*(n-1+t);
return 0;
}