var
  n, min, k, c: integer;
begin
  readln(n);
  k := trunc(sqrt(n));
  if (n mod k = 0) then c:=n div k
    else
  c:=(n div k)+1;
  min := c * k * 2 + (n mod c) *2 + c + k;
  if (n mod c <> 0) then
  dec(min,2*c);
  writeln(min);
  readln;
end.