{
TASK:n23
LANG:PASCAL
}

Var
 N, NN : Word;
 Nm, Num : LongInt; {int64}
 Bl : Boolean;

Begin
 ReadLn(N); Nm := 1;
 Repeat
  Repeat
   Inc(Nm);

   Bl := True;
   Num := Nm;
   Repeat
    If not ((Num mod 10) in [2, 3]) then
    Begin
     Bl := False;
     {Break;}
    end;

    Num := Num div 10;
   Until Num = 0;
  Until Bl;

  {WriteLn(Nm);}
  Num := Nm; NN := 0;

  While (Num mod 2 = 0) and (NN < N) do
  Begin
   Num := Num div 2;
   Inc(NN);
  end;

  If NN = N then
  Begin
   WriteLn(Nm);
   Halt;
  end;
 Until False;
end.