program fractii;
var f:text;
nr,k,n,a,p,b,q:longint;
begin
assign(f,'fractii.in');reset(f);
read(f,n);close(f);
nr:=1+2*(n-1);
for p:=2 to n do
   for k:=2 to p-1 do begin
       a:=p;b:=k;
       while a*b<>0 do
             if a>b then a:=a mod b
                    else b:=b mod a;
       if a+b=1 then nr:=nr+2;
       end;
assign(f,'fractii.out');rewrite(f);
write(f,nr);close(f);
end.