python3, 145 bytes

Result

WA

Duration

508ms

Code [DL]

a,b,c,d,e,f,g,h,i=[int(b)-a for a,b in zip([*map(int,input().split())]*3,open(0).read().split())]
print((a*e*i+b*f*g+c*d*h-a*h*f-b*i*d-c*g*e)//6)

stdin

71 09 44
82 40 36
59 19 17
07 69 21

stdout

stderr

Traceback (most recent call last):
  File "/volume/CODE", line 1, in <module>
    a,b,c,d,e,f,g,h,i=[int(b)-a for a,b in zip([*map(int,input().split())]*3,open(0).read().split())]
ValueError: not enough values to unpack (expected 9, got 0)

strace