by@_gacin
AC
448ms
a={}for k=1,4 do for s in string.gmatch(io.read(),"%w+")do a[#a+1]=s end end for z=1,9 do a[z]=a[z]-a[10+~-z%3]end s=0 for z=1,3 do q=-~z%3;s=s+a[z]*(a[7+z%3]*a[4+q]-a[4+z%3]*a[7+q])end print(math.floor(s/6))
05 64 31 72 71 37 46 68 58 20 36 70
7583