var i,n,j,a,b,cn,r:longint;
    f,g:text;
begin
     assign(f,'fractii.in');
     assign(g,'fractii.out');
     reset(f);
     rewrite(g);
     readln(f,n);
     cn:=0;
     for i:=1 to n do
         for j:=1 to n do
             begin
                  if (i>2) and (i=j) then break;
                  a:=i;
                  b:=j;
                  while a mod b<>0 do
                        begin
                             r:=a mod b;
                             a:=b;
                             b:=r;
                        end;
                  if b=1 then inc(cn);
             end;
     write(g,cn);
     close(f);
     close(g);
end.