cy, 72 bytes

Result

WA

Duration

582ms

Code [DL]

"\\#{require'matrix';p Matrix[*$<.map{|x|eval"A=1,"+x.split*?,}].det/6}"

stdin

89 88 05
02 42 35
09 98 23
08 79 08

stdout

stderr

RubyError
	@ `"\\#{require'matrix';p Matrix[*$<.map{|x|eval"A=1' (0:0)
/root/cy.rb:552:in `block in runMeth': undefined method `call' for nil:NilClass (NoMethodError)
	from /root/cy.rb:665:in `block in exec'
	from /root/cy.rb:660:in `each'
	from /root/cy.rb:660:in `exec'
	from /root/cy.rb:777:in `block (3 levels) in <main>'
	from /root/cy.rb:844:in `<main>'

strace