diff --git a/buisnesslogic/src/main/java/com/plannaplan/entities/Groups.java b/buisnesslogic/src/main/java/com/plannaplan/entities/Groups.java
index eccbdc5..1a2b5a3 100755
--- a/buisnesslogic/src/main/java/com/plannaplan/entities/Groups.java
+++ b/buisnesslogic/src/main/java/com/plannaplan/entities/Groups.java
@@ -1,10 +1,14 @@
 package com.plannaplan.entities;
 
+import java.util.HashSet;
+import java.util.Set;
+
 import javax.persistence.Entity;
 import javax.persistence.GeneratedValue;
 import javax.persistence.GenerationType;
 import javax.persistence.Id;
 import javax.persistence.JoinColumn;
+import javax.persistence.ManyToMany;
 import javax.persistence.ManyToOne;
 
 import com.plannaplan.types.GroupType;
@@ -36,23 +40,36 @@ public class Groups {
     private Lecturer lecturer;
     private Integer zajCykId;
     private Integer grNr;
+    @ManyToMany(mappedBy = "studentRegisteredGrups")
+    private Set<User> registeredStudents;
+
+    public Set<User> getRegisteredStudents() {
+        return this.registeredStudents;
+    }
+
+    public void assignUser(User user) {
+        if (this.registeredStudents == null) {
+            this.registeredStudents = new HashSet<>();
+        }
+        this.registeredStudents.add(user);
+    }
 
     public Groups() {
     }
 
-    public Integer getGr_nr() {
+    public Integer getGrNr() {
         return grNr;
     }
 
-    public void setGr_nr(Integer grNr) {
+    public void setGrNr(Integer grNr) {
         this.grNr = grNr;
     }
 
-    public Integer getZaj_cyk_id() {
+    public Integer getZajCykId() {
         return zajCykId;
     }
 
-    public void setZaj_cyk_id(Integer zajCykId) {
+    public void setZajCykId(Integer zajCykId) {
         this.zajCykId = zajCykId;
     }
 
diff --git a/buisnesslogic/src/main/java/com/plannaplan/entities/User.java b/buisnesslogic/src/main/java/com/plannaplan/entities/User.java
index 422ae1f..26cac76 100755
--- a/buisnesslogic/src/main/java/com/plannaplan/entities/User.java
+++ b/buisnesslogic/src/main/java/com/plannaplan/entities/User.java
@@ -1,13 +1,18 @@
 package com.plannaplan.entities;
 
 import java.sql.Timestamp;
+import java.util.HashSet;
+import java.util.Set;
 import java.util.UUID;
 import java.util.concurrent.TimeUnit;
 
+import javax.persistence.CascadeType;
 import javax.persistence.Entity;
 import javax.persistence.GeneratedValue;
 import javax.persistence.GenerationType;
 import javax.persistence.Id;
+import javax.persistence.JoinTable;
+import javax.persistence.ManyToMany;
 
 import com.plannaplan.models.UserApiResponse;
 import com.plannaplan.types.UserRoles;
@@ -33,6 +38,20 @@ public class User {
     private String refreshToken;
     private Timestamp tokenUsageDate;
     private Integer ranking;
+    @ManyToMany(cascade = CascadeType.ALL)
+    @JoinTable
+    private Set<Groups> studentRegisteredGrups;
+
+    public Set<Groups> getStudentRegisteredGrups() {
+        return this.studentRegisteredGrups;
+    }
+
+    public void claimGroup(Groups group) {
+        if (this.studentRegisteredGrups == null) {
+            this.studentRegisteredGrups = new HashSet<>();
+        }
+        this.studentRegisteredGrups.add(group);
+    }
 
     public User() {
     }
diff --git a/buisnesslogic/src/test/java/com/plannaplan/services/AssignmentServiceTest.java b/buisnesslogic/src/test/java/com/plannaplan/services/AssignmentServiceTest.java
index 10ec7cf..93bc604 100755
--- a/buisnesslogic/src/test/java/com/plannaplan/services/AssignmentServiceTest.java
+++ b/buisnesslogic/src/test/java/com/plannaplan/services/AssignmentServiceTest.java
@@ -18,8 +18,10 @@ import javax.management.relation.Role;
 
 import com.plannaplan.entities.Assignment;
 import com.plannaplan.entities.Commision;
+import com.plannaplan.entities.Groups;
 import com.plannaplan.entities.User;
 import com.plannaplan.types.UserRoles;
+import com.plannaplan.types.WeekDay;
 
 import org.junit.Test;
 
@@ -36,6 +38,8 @@ public class AssignmentServiceTest {
     private CommisionService comServie;
     @Autowired
     private UserService userService;
+    @Autowired
+    private GroupService groupService;
 
     @Test
     public void shouldSaveAssignment() {
@@ -67,11 +71,37 @@ public class AssignmentServiceTest {
     @DirtiesContext(methodMode = MethodMode.BEFORE_METHOD)
     public void shouldPerformAcceptAlgorythm() {
         final Random generator = new Random();
+        final User user1 = this.userService.save(new User(null, null,
+                "shouldPerformAcceptAlgorythm-" + UUID.randomUUID().toString() + "@AssignmentService.test", null,
+                UserRoles.STUDENT, generator.nextInt(400) + 100));
+
+        final User user2 = this.userService.save(new User(null, null,
+                "shouldPerformAcceptAlgorythm-" + UUID.randomUUID().toString() + "@AssignmentService.test", null,
+                UserRoles.STUDENT, generator.nextInt(400) + 100));
+
         IntStream.range(0, 1700).forEach(i -> {
             this.userService.save(new User(null, null,
                     "shouldPerformAcceptAlgorythm-" + UUID.randomUUID().toString() + "@AssignmentService.test", null,
                     UserRoles.STUDENT, generator.nextInt(400) + 100));
         });
+
+        IntStream.range(0, 418).forEach(i -> {
+            this.groupService.save(new Groups(generator.nextInt(80) + 20, null, null,
+                    generator.nextInt(9) * 30 + 9 * 30, WeekDay.getDay(generator.nextInt(5)), null));
+        });
+
+        IntStream.range(0, 12).forEach(i -> {
+            user1.claimGroup(this.groupService.save(new Groups(generator.nextInt(80) + 20, null, null,
+                    generator.nextInt(9) * 30 + 9 * 30, WeekDay.getDay(generator.nextInt(5)), null)));
+        });
+        this.userService.save(user1);
+
+        IntStream.range(0, 12).forEach(i -> {
+            user2.claimGroup(this.groupService.save(new Groups(generator.nextInt(80) + 20, null, null,
+                    generator.nextInt(9) * 30 + 9 * 30, WeekDay.getDay(generator.nextInt(5)), null)));
+        });
+        this.userService.save(user2);
+
         this.service.callAcceptAlgorythm();
         System.out.println("-X_-x-x-x-_X-x-x-x-X_-x-x-x-");
     }