Eulero

Eulero ("Graeco-Latin Square", "Euler Square") is a puzzle with letters and digits. The goal is to fill in the grid with symbols according to the following rules:

• Each cell contains one letter and one digit.
• Every row and every column contains each letter and each digit exactly once.
• No two cells contain the same pair of symbols.

Cross+A can solve puzzles from 3 x 3 to 7 x 7 (Graeco-Latin square 6 x 6 does not exist).