var s:int64;
    f,g:text;
    x,i,m,n:longint;
    a,b:array[1..1000000] of word;
begin
assign(f,'fractii.in');reset(f);
assign(g,'fractii.out');rewrite(g);
read(f,n);
s:=n;
for i:=2 to n do begin
    x:=i;
    while x<=n do begin
          inc(a[x]);
          inc(x,i);
          inc(b[i]);
          end;
    end;
for i:=2 to n div 2 do
    inc(s,n-b[i]);
for i:=n div 2+1 to n do
    inc(s,n-a[i]);
writeln(g,s);
close(f);
close(g);
end.