My thanks to Skimask and Steve B for their advice. For Bingo, there really is no need to use the letters. Each letter has 15 places, i.e. B goes from 1 to 15, I goes from 16 to 30, N 31 to 45, G 46 to 60, and finally O from 61 to 75. Of course, as with any other problem, there are probably a lot of ways to do the program, but I like the idea of bit arrays and will try to experiment with it.