Tohu wa Vohu
This puzzle was invented by Adolfo Zanellati
Puzzle and Goal
An unsolved puzzle consists of a square grid. Some cells contain one of two markers, such as "T" and "V".
The goal is to place one of the two markers in each cells, according to the rules.
The solved grid must satisfy the following conditions:
Each of the two markers must appear N/2 times per rank, where N is the size of the grid.
Three of the same marker in a consecutive line in any rank is not allowed.
Binairo; Binary Puzzle; Eins und Zwei; Zernero