− v 3 u 3 + 2 v 2 u 3 + v 3 u 2 − v 2 u 2 + u 2 + v 3 u − v u + u + 2 v − 1 {\displaystyle -v^{3}u^{3}+2v^{2}u^{3}+v^{3}u^{2}-v^{2}u^{2}+u^{2}+v^{3}u-vu+u+2v-1}
