Eulero

Eulero combines elements of Latin squares and Sudoku. Enter a letter and a number into each cell to create a Graeko-Latin (Euler) square.

Rules: Enter one number from the range 1-N and one letter from the range A-N in each cell of the NxN grid. Each letter and number must appear exactly once in each row and column. Each letter and number combination must appear exactly once in the entire grid.