r= x^24 - x^22 + x^20 - x^18 + x^16 - x^14 + x^12 - x^10 + x^8 - x^6 + x^4 - x^2 + 1 q= (x^30 - 2*x^28 + x^26 + x^4 + 2*x^2 + 1) / 4 P= x^15 - 2*x^14 + x^13 + x^2 + 2*x + 1 v= x^2