Alice and Bob are getting bored so they decided to play a game.
Alice has n cards having the first n odd numbers written on them. He removes one of the cards at random and hands the remaining n-1 cards to Bob. Help Bob to find the value of the card Alice has removed.
The first line contains n the numbers of cards Alice has.
The second line contains n-1 space-separated integers representing the values of cards that Bob got.
Print the value of card Alice removed.
The first 5 odd numbers are 1, 3, 5, 7 and 9 out of which 7 is missing.