program sada;
var i,j,n,nr:longint;
f,g:text;
begin
assign (f,'fractii.in');
reset (f);
assign (g,'fractii.out');
rewrite (g);
readln (f,n);
nr:=n;
for i:=2 to n do
    for j:=1 to n do if i>j then begin if (j=1) or (i mod j<>0)  then  nr:=nr+1; end
                            else if j mod i<>0  then nr:=nr+1;
write (g,nr);
close (f);
close (g);
end.