This program was written by Chris Dannemiller Lights out is a registered trademark of Tiger Electronics To make a file simple put the matrix in a file seprated by commas for each row and each row is seperated by a return look at the accoming lvl??.txt files for examples on this. I would like all 50 levels in this file please send them the web address where i found the formula is: www.whitman.edu/Departments/Mathematics/lights_out