It would depend on the signal of the last element of the sum.
But we'd have to have (how do you write polynomion, or whatever

, btw?) a pair of +1 with -1 for that to equal zero.
That is, we'd need
0=1-1+1-1+1-1+...1-1+1-1+1-1
RHS=1-(1-1)-(1-1)-(1-...1)-(1-1)-(1-1)-1