d-dmd, 195 bytes

Result

WA

Duration

499ms

Code [DL]

import std.stdio;void main(){int[30] a;int i;for(;readf(" %d",&a[i]);i++)if(i>2)a[i]-=a[i%3];printf("%d\n",(a[3]a[7]a[11]+a[4]a[8]a[9]+a[5]a[10]a[6]-a[5]a[7]a[9]-a[8]a[10]a[3]-a[4]a[11]a[6])/6);}

stdin

49 93 08
62 15 71
99 67 76
14 56 60

stdout

stderr

/volume/CODE.d(1): Error: found `a` when expecting `)`
/volume/CODE.d(1): Error: found `a` when expecting `,`
/volume/CODE.d(1): Error: found `a` when expecting `,`
/volume/CODE.d(1): Error: found `a` when expecting `,`
/volume/CODE.d(1): Error: found `a` when expecting `,`
/volume/CODE.d(1): Error: found `a` when expecting `,`
/volume/CODE.d(1): Error: found `a` when expecting `,`
/volume/CODE.d(1): Error: found `a` when expecting `,`
/volume/CODE.d(1): Error: found `a` when expecting `,`
/volume/CODE.d(1): Error: found `a` when expecting `,`
/volume/CODE.d(1): Error: found `a` when expecting `,`
/volume/CODE.d(1): Error: found `a` when expecting `,`
/volume/CODE.d(1): Error: found `)` when expecting `;` following statement
/volume/CODE.d(1): Deprecation: use `{ }` for an empty statement, not `;`
Failed: ["/usr/bin/dmd", "-v", "-o-", "/volume/CODE.d", "-I/volume"]

strace