set/P s=
set/a "g=%s:~18%-(a=%s:~0%),h=%s:~21%-(b=%s:~3%),i=%s:~24%-(c=%s:~6%),j=%s:~27%-a,k=%s:~30%-b,l=%s:~33%-c,w=(%s:~12%-b)*(i*j-g*l),w+=(%s:~15%-c)*(g*k-h*j),y=(w+(%s:~9%-a)*(h*l-i*k))/6"
echo %y%