I'm just sharing a quick thought here - on the need to work out exactly what you want to do with your program before you write the code.  If you've plenty of time to waste, then by all means write code without thinking things through ... but there are better ways.  Work out your inputs. Work out your outputs. Work out how you (manually) get from one to the other.  Only start coding when you know what you're trying to acheived and have a good idea how you're going to achieve it.

If you're making a new journey, you look up maps and timetables ahead of time, don't you?  So why do so many people fail to do the same thing when they're progamming?  

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