Playoff Party

Four teams have reached IPL Playoffs and are having party together . Yuzi wanted to play some brain game so he gave other players a sequence $A$ consisting of $N$ integers. He asked other players to make several steps. In a single step he can choose an element of the sequence (let's denote it $A[k]$) and delete it, at that moment all elements equal to $A[k]+1$ and $A[k]-1$ also must be deleted fro