TODO list. This is mostly so i can plan more granularly and remember small stuff i was working on last time and what i should prioritise first. 
This is not my overall big planning board. (1 highest prio, 10 lowest)  

1 - Have a big long think about how validate_N should work
1 - implement validate_N
1 - Perform tests on validate_N
2 - add some sort of length check
3 - Have a big long think about how the strings will be processed and translate in to actually doing things in the program.