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%