I've made a spreadsheet where you can just assign letters to each symbol and see how the map changes

https://docs.google.com/spreadsheets/d/1h5uRLE51IYupTY4p94jaS77EQvwRwEu0xTKHR_DC5Bg/edit?usp=sharing

just duplicate the original sheet into a new one if you want to make changes, so we can preserve the original. The numbers 1,2,3... associated with each letter are just the order in which that letter figures in the map, reading from left to right top to bottom