diff --git a/core-java-modules/core-java-jar/src/test/java/com/baeldung/jar/JarAppUnitTest.java b/core-java-modules/core-java-jar/src/test/java/com/baeldung/jar/JarAppUnitTest.java
index 707ce79624..fc40aa01c5 100644
--- a/core-java-modules/core-java-jar/src/test/java/com/baeldung/jar/JarAppUnitTest.java
+++ b/core-java-modules/core-java-jar/src/test/java/com/baeldung/jar/JarAppUnitTest.java
@@ -3,10 +3,14 @@ package com.baeldung.jar;
 import org.junit.Assert;
 import org.junit.jupiter.api.Test;
 
+import java.util.regex.Pattern;
+
 public class JarAppUnitTest {
 
     @Test
     public void findClassTest(){
-        Assert.assertTrue(JarApp.findObjectMapperClass().endsWith("jackson-databind-2.13.3.jar"));
+        Pattern databindPattern = Pattern.compile(".*jackson-databind-(\\d)+\\.(\\d)+\\.(\\d)\\.jar$");
+
+        Assert.assertTrue(databindPattern.matcher(JarApp.findObjectMapperClass()).matches());
     }
 }
diff --git a/core-java-modules/core-java-leetcode/src/test/java/com/baeldung/leetcode/magicsquare/GenerationUnitTest.java b/core-java-modules/core-java-lang-math-3/src/test/java/com/baeldung/magicsquare/GenerationUnitTest.java
similarity index 95%
rename from core-java-modules/core-java-leetcode/src/test/java/com/baeldung/leetcode/magicsquare/GenerationUnitTest.java
rename to core-java-modules/core-java-lang-math-3/src/test/java/com/baeldung/magicsquare/GenerationUnitTest.java
index 308c655bd1..f02200462e 100644
--- a/core-java-modules/core-java-leetcode/src/test/java/com/baeldung/leetcode/magicsquare/GenerationUnitTest.java
+++ b/core-java-modules/core-java-lang-math-3/src/test/java/com/baeldung/magicsquare/GenerationUnitTest.java
@@ -1,4 +1,4 @@
-package com.baeldung.leetcode.magicsquare;
+package com.baeldung.magicsquare;
 
 import org.junit.jupiter.api.Test;
 
diff --git a/core-java-modules/core-java-leetcode/src/test/java/com/baeldung/leetcode/magicsquare/MagicSquare.java b/core-java-modules/core-java-lang-math-3/src/test/java/com/baeldung/magicsquare/MagicSquare.java
similarity index 96%
rename from core-java-modules/core-java-leetcode/src/test/java/com/baeldung/leetcode/magicsquare/MagicSquare.java
rename to core-java-modules/core-java-lang-math-3/src/test/java/com/baeldung/magicsquare/MagicSquare.java
index 5e16f2e0db..b6e7ac24f5 100644
--- a/core-java-modules/core-java-leetcode/src/test/java/com/baeldung/leetcode/magicsquare/MagicSquare.java
+++ b/core-java-modules/core-java-lang-math-3/src/test/java/com/baeldung/magicsquare/MagicSquare.java
@@ -1,4 +1,4 @@
-package com.baeldung.leetcode.magicsquare;
+package com.baeldung.magicsquare;
 
 import org.junit.platform.commons.util.StringUtils;
 
@@ -172,7 +172,9 @@ public class MagicSquare {
                 int value = getCell(x, y);
                 if (value == 0) {
                     sb.append(" ");
-                    sb.append(".".repeat(largestNumberLength));
+                    for (int i = 0; i < largestNumberLength; ++i) {
+                        sb.append(".");
+                    }
                     sb.append(" ");
                 } else {
                     sb.append(String.format(formatString, value));
diff --git a/core-java-modules/core-java-leetcode/src/test/java/com/baeldung/leetcode/magicsquare/ValidationUnitTest.java b/core-java-modules/core-java-lang-math-3/src/test/java/com/baeldung/magicsquare/ValidationUnitTest.java
similarity index 92%
rename from core-java-modules/core-java-leetcode/src/test/java/com/baeldung/leetcode/magicsquare/ValidationUnitTest.java
rename to core-java-modules/core-java-lang-math-3/src/test/java/com/baeldung/magicsquare/ValidationUnitTest.java
index 93f36931e6..6b0ec600bb 100644
--- a/core-java-modules/core-java-leetcode/src/test/java/com/baeldung/leetcode/magicsquare/ValidationUnitTest.java
+++ b/core-java-modules/core-java-lang-math-3/src/test/java/com/baeldung/magicsquare/ValidationUnitTest.java
@@ -1,4 +1,4 @@
-package com.baeldung.leetcode.magicsquare;
+package com.baeldung.magicsquare;
 
 import org.junit.jupiter.api.Test;
 
diff --git a/core-java-modules/core-java-leetcode/pom.xml b/core-java-modules/core-java-leetcode/pom.xml
deleted file mode 100644
index eb91308c64..0000000000
--- a/core-java-modules/core-java-leetcode/pom.xml
+++ /dev/null
@@ -1,39 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0"
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-    <modelVersion>4.0.0</modelVersion>
-    <artifactId>core-java-leetcode</artifactId>
-    <name>core-java-leetcode</name>
-    <packaging>jar</packaging>
-
-    <parent>
-        <groupId>com.baeldung</groupId>
-        <artifactId>parent-modules</artifactId>
-        <version>1.0.0-SNAPSHOT</version>
-        <relativePath>../../pom.xml</relativePath>
-    </parent>
-
-    <dependencies>
-    </dependencies>
-
-    <build>
-        <plugins>
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-compiler-plugin</artifactId>
-                <version>${maven-compiler-plugin.version}</version>
-                <configuration>
-                    <source>${maven.compiler.source.version}</source>
-                    <target>${maven.compiler.target.version}</target>
-                </configuration>
-            </plugin>
-        </plugins>
-    </build>
-
-    <properties>
-        <maven.compiler.source.version>11</maven.compiler.source.version>
-        <maven.compiler.target.version>11</maven.compiler.target.version>
-    </properties>
-
-</project>
diff --git a/core-java-modules/pom.xml b/core-java-modules/pom.xml
index a6f0382186..e9bb86e500 100644
--- a/core-java-modules/pom.xml
+++ b/core-java-modules/pom.xml
@@ -108,7 +108,6 @@
         <module>core-java-lang-operators-2</module>
         <module>core-java-lang-syntax</module>
         <module>core-java-lang-syntax-2</module>
-        <module>core-java-leetcode</module>
         <module>core-java-locale</module>
         <module>core-java-networking</module>
         <module>core-java-networking-2</module>