r= x^40 - x^30 + x^20 - x^10 + 1 q= ( x^54 + 2*x^52 + x^50 + x^4 - 2*x^2 + 1 ) / 4 P= x^27 + 2*x^26 + x^25 + x^2 - 2*x + 1 v= x^2