program fractii;
var f,g:text;
    i,j,ci,cj:longint;
    c,n:int64;
begin
assign(f,'fractii.in');
assign(g,'fractii.out');
reset(f);
rewrite(g);
read(f,n);
c:=n*n;
for i:=2 to n do
  begin
    for j:=i to n do
        if (i mod j<>0)then c:=c-1;
  end;
writeln(g,c);
close(f);
close(g);
end.