Binary Calculation

In last lecture Chef was teaching about binary number representation. Today he came up with an interesting task to check the understanding of student about binary number. So this task is, Students are given a collection of $N$ positive integers $A$0, $A$1, $A$2 …, $A$N-1, and then they have to compute the sum of square $∑(Ai)^2$ as maximum as possible for all $Ai$ where( 0 $\leq$ i $\leq$ N-1 )