flippingoperationexample

Selected card          State of all cards after flipping operation done
   2                                 1 1 1 0 0 0 0
   3                                 1 0 0 1 0 0 0
   4                                 1 0 1 0 1 0 0
   5                                 1 0 1 1 0 1 0
   6                                 1 0 1 1 1 0 1
   7                                 0 0 1 1 1 1 0
   1                                 1 1 1 1 1 1 1