a 7 z 9 + a 5 z 9 + a 8 z 8 + 2 a 6 z 8 + a 4 z 8 − 7 a 7 z 7 − 7 a 5 z 7 − 7 a 8 z 6 − 14 a 6 z 6 − 7 a 4 z 6 + 15 a 7 z 5 + 14 a 5 z 5 + a z 5 + 15 a 8 z 4 + 27 a 6 z 4 + 13 a 4 z 4 + 2 a 2 z 4 + z 4 − 13 a 7 z 3 − 11 a 5 z 3 − 2 a z 3 − 11 a 8 z 2 − 15 a 6 z 2 − 6 a 4 z 2 − 5 a 2 z 2 − 3 z 2 + 5 a 7 z + 6 a 5 z − a z + a 8 + a 6 + a 2 + 2 {\displaystyle a^{7}z^{9}+a^{5}z^{9}+a^{8}z^{8}+2a^{6}z^{8}+a^{4}z^{8}-7a^{7}z^{7}-7a^{5}z^{7}-7a^{8}z^{6}-14a^{6}z^{6}-7a^{4}z^{6}+15a^{7}z^{5}+14a^{5}z^{5}+az^{5}+15a^{8}z^{4}+27a^{6}z^{4}+13a^{4}z^{4}+2a^{2}z^{4}+z^{4}-13a^{7}z^{3}-11a^{5}z^{3}-2az^{3}-11a^{8}z^{2}-15a^{6}z^{2}-6a^{4}z^{2}-5a^{2}z^{2}-3z^{2}+5a^{7}z+6a^{5}z-az+a^{8}+a^{6}+a^{2}+2}
