Lua translation

The description looks purely mathematical and doesn't specify data types and implementation details, so I'd expect that the answer for [[1,0,0],[1,0,0],[1,0,0],[1,0,0],[1,0,0],[1,0,0]] should be 2, but the reference solution returns 1, so:

• the reference solution is incorrect;
• and edge case test like [[1,0,0],[1,0,0],[1,0,0],[1,0,0],[1,0,0],[1,0,0]] should be added.