Не понимаю где ошибка.
Занимаюсь в целом программированием 3 недели (как хобби)
Проверял на исходном примере и на примерах, которые нашел на форуме. Ответы верны. Сюда загружаю выдаёт ошибку.

example = {'i' : 1, 'j' : 1, 'a' : 2, 'b' : 2, 'c' : 2,
               'd' : 3, 'e' : 3, 'f' : 3, 'g' : 4, 'h' : 4,
               'k' : 5, 'l' : 5, 'm' : 6, 'n' : 6, 'p' : 7,
               'r' : 7, 's' : 7, 't' : 8, 'u' : 8, 'v' : 8,
               'w' : 9, 'x' : 9, 'y' : 9, 'o' : 0, 'q' : 0, 'z' : 0}

while True:
    number = input()
    if int(number) == -1:
        break

    num_words = int(input())
    words = {}
    k = 500

    for i in range(num_words):
        word = input()
        if len(word) < k:
            k = len(word)
        key_word = ""
        for a in word:
            key_word += str(example.get(a))
        words[int(key_word)] = word

    answer = []
    loser = ""

    while True:
        copy = number[len("".join(answer)):]
        x = len(copy)
        while x >= k:
            if int(copy[:x]) in words.keys():
                if words[int(copy[:x])] != loser:
                    answer.append(words[int(copy[:x])])
                    copy = copy[x:]
                    x = len(copy) + 1
            x -= 1
        if len(answer) == 0:
            break
        elif len("".join(answer)) != len(number):
            loser = answer.pop()
        elif len("".join(answer)) == len(number):
            break

    if len(answer) == 0:
        print("No solution.")
    else:
        ans = " ".join(answer)
        print(ans)

12345
5
iad
i
adgk
g
k
-1

should print "i adgk" instead of "iad g k"