lua, 156 bytes

Result

AC

Duration

474ms

Code [DL]

X={}for i=-3,8 do X[i]=io.read("*n")-(X[i%3-3]or 0)end
print((X[0]*X[4]*X[8]+X[1]*X[5]*X[6]+X[2]*X[3]*X[7]-X[0]*X[5]*X[7]-X[1]*X[3]*X[8]-X[2]*X[4]*X[6])//6)

stdin

53 53 03
30 30 89
50 92 14
05 05 86

stdout

15533

stderr

strace