For part 1, it took way longer than necessary since I read the
instructions over and over again. Gotta love AOC WOT.
Part 2 was a PITA. I got stuck at the last 2 examples since I at the
time did not find any clever way to determine which of the 2 outputs for
'1' mapped to c and f.
Since I already spent far too much time and effort, a try/except with
ValueError (digits.index will fail if c and f are flipped wrong) will do
for now.
There is probably a more efficient and smart way to do this.
