powershell, 133 bytes

Result

WA

Duration

1299ms

Code [DL]

$a =(Read-Host).Split(" ")
$b=@()
$b+=(Read-Host).Split(" ")-$a
$b+=(Read-Host).Split(" ")-$a
$b+=(Read-Host).Split(" ")-$a
echo($b)

stdin

55 23 18
16 02 84
37 09 68
06 78 66

stdout

55 23 18
16 02 84
37 09 68
06 78 66

stderr

Method invocation failed because [System.String[]] does not contain a method named 'op_Subtraction'.
At line:3 char:1
+ $b+=(Read-Host).Split(" ")-$a
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo          : InvalidOperation: (op_Subtraction:String) [], RuntimeException
+ FullyQualifiedErrorId : MethodNotFound
 
Method invocation failed because [System.String[]] does not contain a method named 'op_Subtraction'.
At line:4 char:1
+ $b+=(Read-Host).Split(" ")-$a
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo          : InvalidOperation: (op_Subtraction:String) [], RuntimeException
+ FullyQualifiedErrorId : MethodNotFound
 
Method invocation failed because [System.String[]] does not contain a method named 'op_Subtraction'.
At line:5 char:1
+ $b+=(Read-Host).Split(" ")-$a
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo          : InvalidOperation: (op_Subtraction:String) [], RuntimeException
+ FullyQualifiedErrorId : MethodNotFound
 

strace