From 4481e9cc18f815414af32f99a02122bc5f57c2d1 Mon Sep 17 00:00:00 2001
From: Jethro Stapelbroek <js@jethrostapelbroek.nl>
Date: Wed, 19 Jul 2023 20:40:14 +0200
Subject: [PATCH] Kleptography

---
 kleptography.py | 13 +++++++++++++
 1 file changed, 13 insertions(+)
 create mode 100644 kleptography.py

diff --git a/kleptography.py b/kleptography.py
new file mode 100644
index 0000000..0c4676e
--- /dev/null
+++ b/kleptography.py
@@ -0,0 +1,13 @@
+n, m = map(int, input().split())
+knowntext = input()
+ciphertext = input()
+plaintext = [""] * m
+for i in range(n):
+    plaintext[-n + i] = knowntext[i]
+
+for i in range(m - 1, -1, -1):
+    char = chr((ord(ciphertext[i]) - ord(plaintext[i])) % 26 + 97)
+    if i - n >= 0:
+        plaintext[i - n] = char
+
+print("".join(plaintext))