diff --git a/README.md b/README.md
index 201dab7..0d3feee 100644
--- a/README.md
+++ b/README.md
@@ -13,4 +13,11 @@ Coder - [Coder.java](src%2Fmain%2FCoder.java)
 
 Decoder - [Decoder.java](src%2Fmain%2FDecoder.java)
 
-Methods that are used in the encoder and decoder - [Helpers.java](src%2Fmain%2FHelpers.java)
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+Methods that are used in the encoder and decoder - [Helpers.java](src%2Fmain%2FHelpers.java)
+
+# How to run it?
+1. You must have the JRE (minimum version 8) installed
+2. Download latest [release-file.jar](https://github.com/bruch-alex/hamming-code/releases)
+3. Open Terminal in directory, where you saved `.jar` file 
+4. Copy this command `java -cp hamming-code-VERSION-NUMBER.jar Main`, replace VERSION_NUMBER with current version and run it. 
+5. Just follow instructions on the screen :D
diff --git a/pom.xml b/pom.xml
index c34dc28..ebf8f84 100644
--- a/pom.xml
+++ b/pom.xml
@@ -6,7 +6,7 @@
 
     <groupId>com.mycompany.app</groupId>
     <artifactId>hamming-code</artifactId>
-    <version>1.0-SNAPSHOT</version>
+    <version>2024071400</version>
 
     <properties>
         <maven.compiler.source>11</maven.compiler.source>
@@ -41,7 +41,8 @@
                         </goals>
                         <configuration>
                             <transformers>
-                                <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
+                                <transformer
+                                        implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                                     <mainClass>Main</mainClass>
                                 </transformer>
                             </transformers>
@@ -58,6 +59,11 @@
             <artifactId>jline</artifactId>
             <version>3.26.2</version>
         </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>RELEASE</version>
+            <scope>compile</scope>
+        </dependency>
     </dependencies>
-    
 </project>
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diff --git a/src/main/java/Coder.java b/src/main/java/Coder.java
index 55c5b87..f26c3ce 100644
--- a/src/main/java/Coder.java
+++ b/src/main/java/Coder.java
@@ -16,7 +16,7 @@ public static String start(String message) {
      * @param symbol symbol to convert
      * @return binary string with 12 bits
      */
-    private static StringBuilder convertToBinaryWithParityBits(char symbol){
+    public static StringBuilder convertToBinaryWithParityBits(char symbol){
         StringBuilder binaryString = new StringBuilder();
         int val = symbol;
         for (int i = 0; i < 12  ; i++)
diff --git a/src/main/java/Decoder.java b/src/main/java/Decoder.java
index 4d4ea8f..df003ff 100644
--- a/src/main/java/Decoder.java
+++ b/src/main/java/Decoder.java
@@ -36,7 +36,7 @@ private static String fixError(int y, String messageToFix) {
         StringBuilder sb = new StringBuilder(messageToFix);
         if (y != 0)
         {
-            sb.replace(y-1,y,Helpers.changeBit(Character.digit(sb.charAt(y-1),10)));
+            sb.replace(y-1,y,String.valueOf(Helpers.changeBit(Character.digit(sb.charAt(y-1),10))));
         }
         return sb.toString();
     }
diff --git a/src/main/java/Helpers.java b/src/main/java/Helpers.java
index e332907..5148dbc 100644
--- a/src/main/java/Helpers.java
+++ b/src/main/java/Helpers.java
@@ -9,7 +9,6 @@ public static StringBuilder replaceParityBits(StringBuilder binaryMessageWithEmp
     }
 
     /**
-     *
      * @param parityBitPosition - position of parity bit in message (starts with 0)
      * @return value of parity bit (1 or 0)
      */
@@ -41,8 +40,8 @@ public static boolean checkPosition(int i){
      * @param value binary value to be converted
      * @return 1, if value is 0 and return 0, if value is 1.
      */
-    public static String changeBit(int value){
-        return (String.valueOf((value & 1) == 0 ? 1 : 0));
+    public static int changeBit(int value){
+        return (value & 1) == 0 ? 1 : 0;
     }
 
 }
diff --git a/src/test/java/HelpersTest.java b/src/test/java/HelpersTest.java
index 2b55254..26fb340 100644
--- a/src/test/java/HelpersTest.java
+++ b/src/test/java/HelpersTest.java
@@ -1,5 +1,22 @@
-import static org.junit.Assert.*;
+import org.junit.Assert;
+import org.junit.Test;
 
 public class HelpersTest {
 
+    @Test
+    public void changeBitFrom1to0Test(){
+        Assert.assertEquals(1, Helpers.changeBit(0));
+    }
+
+    @Test
+    public void changeBitFrom0to1Test(){
+        Assert.assertEquals(0, Helpers.changeBit(1));
+    }
+
+    @Test
+    public void convertToBinaryWithParityBitsTestSymbol(){
+        StringBuilder sb = new StringBuilder("000011000001");
+        Assert.assertEquals(0, sb.compareTo(Coder.convertToBinaryWithParityBits('a')));
+    }
+
 }
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