set /p q= for /f "tokens=1-12 delims=%q:~8,1% " %%a in ("%q%") do (set /a a=%%d-%%a set /a b=%%e-%%b set /a c=%%f-%%c set /a d=%%g-%%a set /a e=%%h-%%b set /a f=%%i-%%c set /a g=%%j-%%a set /a h=%%k-%%b set /a i=%%l-%%c)set /a v=(a*e*i+b*f*g+c*d*h-a*h*f-b*i*d-c*g*e)/6 echo %v%