from data import words
def zip_function():
    len_words = []
    for word in words:
        len_words.append(len(word))
    words_min_len = min(len_words)
    char_list = []
    zip_records = []
    char_tuple = tuple()
    for i in range(words_min_len):
        for word in words:
            single_char = word[i]
            char_list.append(single_char)
            char_tuple = tuple(char_list)
        char_list = []
        zip_records.append(char_tuple)
    return zip_records
def find_common_prefix():
    records = zip_function()
    tmp = ''
    for record in records:
        if len(set(record)) != 1:
            break
        tmp += record[0]
    return tmp
if __name__ == "__main__":
    print(find_common_prefix())