Comment by Foivos

The main difficulty of part 2 is that there are edge cases that are not covered by the examples. I have appended the example list with some edge cases, so use this list instead:

two1nine eightwothree abcone2threexyz xtwone3four 4nineeightseven2 zoneight234 7pqrstsixteen eighthree sevenine oneight xtwone3four three7one7 eightwothree oooneeone eight7eight