ruby0.49, 84 bytes

Result

WA

Duration

488ms

Code [DL]

a=0
b=1
c=2
d=3
e=3
f=3
g=3
h=3
i=1
print ((a*e*i+b*f*g+c*d*h-a*f*h-b*d*i-c*e*g)/6)

stdin

03 84 55
66 37 05
83 32 99
38 56 72

stdout

1

stderr

strace