Matrix problem

Everything i learned was trough experimenting, jumping into a big pool, i will get there, it's going to be harder but i will get there faster. You helped me a lot in this project, and i thank you for that. i am only one code away from the end, this is my hobby, i don't know any programming, and the electronics part i learned also along the way, mistakes were made, lessons were learned.
first time i saw an arduino i didn't understand a thing, but by looking at the code it makes sense somehow.
if you want to help me out further i will be very thankful, if not, i am thankful so far and i will continue to learn stuff as always.