program fractii;
var a,b,p,k,nr,n:single;
   var f:text;
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.