#!/usr/bin/python
# -*- coding: UTF-8 -*-

import sys



'''

在第一个文件的基础上，添加后续的全部不重复的2字词语。

'''
_list_unique = set()
_list_temp = set()

base_txt_file = sys.argv[1]
new_added_txt_file =sys.argv[2]
base_txt_file_with_added = sys.argv[3]

with open(base_txt_file, 'r', encoding='utf-8-sig') as f:
        for word in f.read().splitlines():
            _list_unique.add(word[0])
            _list_unique.add(word[1])
            _list_unique.add(word[2])
            _list_unique.add(word[3])

print(len(_list_unique))
with open(base_txt_file_with_added, 'w', encoding='utf-8') as final_f:
    with open(new_added_txt_file, 'r', encoding='utf-8-sig') as f:
        for word in f.read().splitlines():
            #print(word)
            if len(word) == 2:
                _list_temp = _list_unique.copy()
                _list_temp.add(word[0])
                _list_temp.add(word[1])

                if len(_list_temp) - len(_list_unique) == 2:
                    _list_unique.add(word[0])
                    _list_unique.add(word[1])
                    final_f.write(word)
                    final_f.write('\n')
            else:
                print(word)
                print(len(word))