module abc148
  sub main()
    dim a as integer, b as integer
    dim ans as integer
    dim i

    a = Console.ReadLine()
    b = Console.ReadLine()

    For i = 1 to 3
      if not (a = i Or b = i) then
        ans = i
        Exit For
      end if
   next

   Console.WriteLine(ans)

  end sub
end module