word_list = ['a',
'b',
'ba',
'bca',
'bda',
'bdca'
             ]
short = ['a', 'c', 'e']

apple = ['sapple', 'apple', 'a']

def longestStringChain(word_list):
    max = 0
    for word in word_list:
        depth = find_subword_count(word, word_list)
        if depth > max:
            max = depth
    return max + 1


def find_subword_count(current_word, word_list):

    if len(current_word) == 1:
        return 0
    max = 0
    for i in range(len(current_word)):
        chars = list(current_word)
        del chars[i]
        subword = ''.join(chars)
        if subword not in word_list:
            continue
        count = 1 + find_subword_count(subword, word_list)
        if max >= count:
            continue
        max = count
    return max



print(longestStringChain(word_list))

print(longestStringChain(short))

print(longestStringChain(apple))