Several decks of cards are displayed, none of which is complete. An assemble of quite a pile of cards is set out in which all the cards are dealt out evenly before playing.
If two people are playing, one card is left out
If three people are playing, two cards are left out
If four people are playing, three cards are left out
If five people are playing, four cards are left out
If six people are playing, five cards and left out
If seven people are playing, no cards are left out
How many cards are in this deck?