by@kurgm
AC
506ms
X={} for i=-3,8 do X[i]=io.read"*n"-(X[i%3-3]or 0) p=-~i%3 q=~-i%3 x=i>5 and x+X[i]*(X[p]*X[q+3]-X[q]*X[p+3])or 0 end print(x//6)
52 33 78 74 11 50 06 06 51 55 90 24
32252