From 5e2f8e3ec531f2fa84ad8e3b2ccaf63bf4523648 Mon Sep 17 00:00:00 2001
From: Drew Winstel <drew@hsv.beer>
Date: Fri, 25 Dec 2020 11:38:30 -0600
Subject: [PATCH] Add Drew's day 25 solution.

It is done.
---
 Drew/drew_day25.py | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
 create mode 100644 Drew/drew_day25.py

diff --git a/Drew/drew_day25.py b/Drew/drew_day25.py
new file mode 100644
index 0000000..dbd8cbd
--- /dev/null
+++ b/Drew/drew_day25.py
@@ -0,0 +1,16 @@
+DOOR_KEY = 9093927
+CARD_KEY = 11001876
+
+
+def establish_secret_key(door_key: int, card_key: int) -> int:
+
+    exponent = 0
+    value = 1
+    while value != card_key:
+        exponent += 1
+        value = 7 * value % 20201227
+    return pow(door_key, exponent, 20201227)
+
+
+if __name__ == "__main__":
+    print(establish_secret_key(DOOR_KEY, CARD_KEY))