program lab24;

var
  i, j, k, n, t: longint;
  a: array [1..1000] of longint;

begin
  read(n);
  i := 1;
  t := 1;

  for j := 1 to 1000 do
  begin
    for k := 1 to i do
    begin
      a[i] := a[i] + t;
      t := t + 2;
    end;
    i := i + 1;
  end;

  writeln(a[n]);

  readln;
  readln;
end.