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).