stuck, 138 bytes

Result

WA

Duration

501ms

Code [DL]

ssss["x:map(int,x.split())"mT"x:[x[3]-e for e in x]"mT]yu]u]u][
______________
1&u5&u6&*u3&u8&*-*u2&u3&u7&*u4&u6&*-*u0&u4&u8&*u5&u7&*-*6/

stdin

69 14 64
03 04 72
36 77 91
16 52 02

stdout

97166-3937053194.3333333

stderr

strace