var j,i,n,nr:longint;
f,g:text;
begin
assign(f,'fractii.in');reset(f);
assign(g,'fractii.out');rewrite(g);
read(f,n);
nr:=0;
for i:=1 to n do
for j:=1 to n do
if j mod i<>0 then inc(nr);
write(g,nr-n);
close(f);
close(g);
end.