题目来自 hacker.org 的Challenge 'Didactic Text' [Crypto]
分析给出的文章，找出暗语。
Four score and seven years ago our fathers brought forth on this continent, a new nation, conceived in Liberty, and dedicated to the proposition that all the men are created equal. Now we are engaged in a great civil war, testing whether that nation, or any nation so conceived and so dedicated, can long endure. We are met on a great battle-field of that war. We have come to dedicate a portion of that field, as a final resting place for those who here gave their lives that that nation might live. It is altogether fitting and proper that we should do this solution. But, in a larger sense, we can not dedicate -- we can not consecrate -- we can not hallow -- this ground. The brave men, living and dead, who struggled here, have consecrated it, is far above our poor power to add or detract. The world will little note, nor long remember what we say here today, but it can never forget what they did here. It is for us the living, rather, to be dedicated here to the brave unfinished work which they who fought here have thus far so nobly advanced. It is rather for us solvers to be here dedicated to the great task remaining before us -- that from these honored dead we take increased devotion to that cause for which they gave the last full measure of devotion -- that we here highly resolve that these dead shall not have died in vain -- that this nation, under God, shall have a new birth of freedom -- and that government of the people, by the people, for the people, shall not perish from the earth.
采用 python 的 difflib模块与原文进行对比分析，找出不同点。
---from difflib import *
file_1 = open("a.txt")
file_2 = open("b.txt")
s_1 = file_1.read()
s_2 = file_2.read()
s = HtmlDiff.make_file(HtmlDiff(),s_1,s_2)
out = open(r"res.html","w")
out.write(s)
---
读入两篇文章到字符串中，使用 difffib 模块中的 HtmlDiff 将比较结果输出为 html 格式。
最后发现给出的文章比原文多了一些单词。
the solution is tody