program fractii;
var p,q,n,c:longint;
        f:text;
begin
assign (f,'fractii.in');reset(f);
read(f,n);
close(f);
p:=1;
c:=0;
q:=1;
repeat
        repeat
                if p mod q<>0 then c:=c+1;
                q:=q+1;
                until q=n+1;
        p:=p+1;
        until p=n+1;
assign(f,'fractii.out');rewrite(f);
write(f,c);
close(f);
end.