lua, 212 bytes

Result

WA

Duration

507ms

Code [DL]

a={}for k=1,4 do for s in string.gmatch(io.read(), "[^%s]+")do a[#a+1]=s end end
for z=1,9 do a[z]=a[z]-a[9+z%3 + 1]end
print(-(a[8]*(a[4]*a[3]-a[1]*a[6])+a[7]*(a[2]*a[6]-a[5]*a[3])+a[9]*(a[1]*a[5]-a[4]*a[2]))/6)

stdin

35 73 70
24 94 83
08 13 10
29 35 62

stdout

-6531.0

stderr

strace