Revert back to lists

This reverts commit 0ed43f497697e9b514bc2288571533d46e34a6ee.
Revert "Filter vector B, so that sum1 = sum2 = 0"

This reverts commit 3aa2491e7afebf0301e9d23e5e590f3976952178.
Revert "First try using integers (bitwise) instead of lists"

This reverts commit 843240e1a9fe1e71d56f5cf4fc72c1fdddad1508.