r= x^8 + x^7 - x^5 - x^4 - x^3 + x + 1 q= (x^12 - x^11 + x^10 - x^7 - 2*x^6 - x^5 + x^2 + 2*x + 1) / 3 P= 3*q_k15method66 v= x