diff --git a/README.md b/README.md
index 0e305d5..d50c7df 100644
--- a/README.md
+++ b/README.md
@@ -51,8 +51,8 @@ is structured.
 | 4     | 2         | 15 days                           | Another friend referral link        |
 | 5     | 1         | 22 days                           | -                                   |
 
->> 1. A referral link allows the person you send it to, to enter foobar.
->> 2. You are asked to fill out your personal info, if you wish, then
+> 1. A referral link allows the person you send it to, to enter foobar.
+> 2. You are asked to fill out your personal info, if you wish, then
  a Google recruiter will contact you soon.
 
 ## Challenges
@@ -80,13 +80,14 @@ is structured.
 
   1. [Expanding Nebula](./src/main/java/foo/bar/l5/readme.txt)(not solved)
 
->> Note that the *readme* files were slightly simplified
+> Note that the *readme* files were slightly simplified
 while solving the corresponding challenge.
 
-## Contribute
+## End message
 
-You are welcome to fork this repository and submit your own solutions.
-Make a pull request and your version will be reviewed within a few days.
+After completing all challenges, Google will give you a base64 encoded message.
+The key to decode it is your foobar username.
+A [script](./scripts/decode.py) was added that prints this message decoded.
 
 ## More information
 
diff --git a/build.gradle b/build.gradle
index 0b332ba..6eff318 100644
--- a/build.gradle
+++ b/build.gradle
@@ -19,15 +19,22 @@ checkstyleTest {
 }
 
 repositories {
-    jcenter()
+    maven {
+        url 'https://repo.maven.apache.org/maven2'
+        name 'Maven Central'
+    }
+}
+
+ext {
+    junitVersion = "5.8.1"
 }
 
 dependencies {
     // This dependency is used by the application.
-    implementation 'com.google.guava:guava:29.0-jre'
+    implementation 'com.google.guava:guava:31.0.1-jre'
     compile group: 'org.openjfx', name: 'javafx', version: '11', ext: 'pom'
 
     // Use JUnit test framework with ParameterizedTest enabled
-    testCompile 'org.junit.jupiter:junit-jupiter-params:5.7.0'
-    testImplementation 'org.junit.jupiter:junit-jupiter-engine:5.5.2'
+    testImplementation "org.junit.jupiter:junit-jupiter-params:${junitVersion}"
+    testImplementation "org.junit.jupiter:junit-jupiter-engine:${junitVersion}"
 }
diff --git a/scripts/decode.py b/scripts/decode.py
new file mode 100755
index 0000000..f4b45d6
--- /dev/null
+++ b/scripts/decode.py
@@ -0,0 +1,12 @@
+#!/usr/local/bin/python3
+"""
+Please fill in MESSAGE and KEY as needed
+"""
+import base64
+
+MESSAGE = ""  # base64 encoded message from Google
+
+KEY = ""  # Your foobar username, usually your google username camel-cased
+
+result = [chr(ord(c) ^ ord(KEY[i % len(KEY)])) for i, c in enumerate(base64.b64decode(MESSAGE).decode("utf-8"))]
+print("".join(result))