diff --git a/src/main/java/mate/academy/Main.java b/src/main/java/mate/academy/Main.java
index 37130e8fa..d6860a3a5 100644
--- a/src/main/java/mate/academy/Main.java
+++ b/src/main/java/mate/academy/Main.java
@@ -1,10 +1,23 @@
 package mate.academy;
-
+import mate.academy.model.User;
 import mate.academy.service.AuthenticationService;
+import mate.academy.service.UserService;
+
+import java.util.Arrays;
+import java.util.List;
 
 public class Main {
-    private static final AuthenticationService authenticationService = new AuthenticationService();
+    private static final AuthenticationService authenticationService;
 
+    static {
+        List<User> users = Arrays.asList(
+                new User("bob@i.ua", "1234"),
+                new User("alice@i.ua", "1234"),
+                new User("john@i.ua", "4321")
+        );
+        UserService userService = new UserService(users);
+        authenticationService = new AuthenticationService(userService);
+    }
     public static void main(String[] args) {
         test("bob@i.ua", "1234", true);
         test("alice@i.ua", "1234", true);
@@ -17,8 +30,8 @@ private static void test(String email, String password, boolean expected) {
         if (expected == actual) {
             System.out.println("Test passed for email: " + email + " and password " + password);
         } else {
-
-            System.out.println("Test passed for email: " + email + " and password " + password);
+            System.out.print("Expected to receive " + expected + ", but was " + actual + ". ");
+            System.out.println("Email: " + email + ", password " + password);
         }
     }
 }
diff --git a/src/main/java/mate/academy/model/User.java b/src/main/java/mate/academy/model/User.java
index 22dc6ff8b..e7a07b529 100644
--- a/src/main/java/mate/academy/model/User.java
+++ b/src/main/java/mate/academy/model/User.java
@@ -1,8 +1,8 @@
 package mate.academy.model;
 
 public class User {
-    private String email;
-    private String password;
+    private final String email;
+    private final String password;
 
     public User(String email, String password) {
         this.email = email;
@@ -14,6 +14,7 @@ public String getEmail() {
     }
 
     public String getPassword() {
+
         return password;
     }
 }
diff --git a/src/main/java/mate/academy/service/AuthenticationService.java b/src/main/java/mate/academy/service/AuthenticationService.java
index 8f7c7c975..2cd7329a2 100644
--- a/src/main/java/mate/academy/service/AuthenticationService.java
+++ b/src/main/java/mate/academy/service/AuthenticationService.java
@@ -1,16 +1,21 @@
 package mate.academy.service;
 
+import mate.academy.model.User;
+
 public class AuthenticationService {
-    /**
-     * Imagine that some user wants to login to your site.
-     * You should check if user credentials (login and password) are valid or not.
-     * All users are stored in <code>UserService</code> class.
-     * @param email - user's email
-     * @param password - user's password
-     * @return true if user by email exists and passed password is equal to user's password.
-     * Return false in any other cases.
-     */
+    private final UserService userService;
+
+    public AuthenticationService(UserService userService) {
+        this.userService = userService;
+    }
+
     public boolean login(String email, String password) {
+        User user = userService.findByEmail(email);
+
+        if (user != null && user.getPassword().equals(password)) {
+            return true;
+        }
+
         return false;
     }
-}
+}
\ No newline at end of file
diff --git a/src/main/java/mate/academy/service/UserService.java b/src/main/java/mate/academy/service/UserService.java
index 1652d7d68..df2cfdbb6 100644
--- a/src/main/java/mate/academy/service/UserService.java
+++ b/src/main/java/mate/academy/service/UserService.java
@@ -1,12 +1,14 @@
 package mate.academy.service;
 
 import mate.academy.model.User;
+import java.util.List;
 
 public class UserService {
-    private static final User[] users = new User[] {
-            new User("bob@i.ua", "1234"),
-            new User("alice@i.ua", "1234")
-    };
+    private final List<User> users;
+
+    public UserService(List<User> users) {
+        this.users = users;
+    }
 
     /**
      * Find user by email. All users are stored in <code>private static final User[] users</code>
@@ -15,6 +17,11 @@ public class UserService {
      * Return <code>null</code> if there is no suitable user
      */
     public User findByEmail(String email) {
+        for (User user : users) {
+            if (user.getEmail().equals(email)) {
+                return user;
+            }
+        }
         return null;
     }
 }