+Original poly.sh is a bit brute forcey
+
+poly-different.sh was required to do part 2 without running out of memory, and
+in a reasonable amount of time. As the parts are in pairs, but the pairs
+overlap, the counting mech will get the count doubled by default, and we also
+have to remember to add 1 count of the char at the start and the end of the
+template.