diff --git a/src/entity/Mark.java b/src/entity/Mark.java
new file mode 100644
index 0000000..18dcc38
--- /dev/null
+++ b/src/entity/Mark.java
@@ -0,0 +1,66 @@
+package entity;
+
+import java.util.List;
+import java.util.Objects;
+
+public class Mark {
+    private String studentId;
+    private String groupId;
+    private List<Integer> mark;
+
+
+    public Mark() {
+    }
+
+    public Mark(String studentId, String groupId, List<Integer> mark) {
+        this.studentId = studentId;
+        this.groupId = groupId;
+        this.mark = mark;
+    }
+
+    public String getStudentId() {
+        return studentId;
+    }
+
+    public void setStudentId(String studentId) {
+        this.studentId = studentId;
+    }
+
+    public String getGroupId() {
+        return groupId;
+    }
+
+    public void setGroupId(String groupId) {
+        this.groupId = groupId;
+    }
+
+    public List<Integer> getMark() {
+        return mark;
+    }
+
+    public void setMark(List<Integer> mark) {
+        this.mark = mark;
+    }
+
+
+    @Override
+    public boolean equals(Object o) {
+        if (o == null || getClass() != o.getClass()) return false;
+        Mark mark1 = (Mark) o;
+        return Objects.equals(studentId, mark1.studentId) && Objects.equals(groupId, mark1.groupId) && Objects.equals(mark, mark1.mark);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(studentId, groupId, mark);
+    }
+
+    @Override
+    public String toString() {
+        return "Mark{" +
+                "studentId='" + studentId + '\'' +
+                ", groupId='" + groupId + '\'' +
+                ", mark=" + mark +
+                '}';
+    }
+}
diff --git a/src/entity/Student.java b/src/entity/Student.java
deleted file mode 100644
index 9ff9844..0000000
--- a/src/entity/Student.java
+++ /dev/null
@@ -1,45 +0,0 @@
-package entity;
-
-public class Student {
-    private User user;
-    private StringBuilder marks = new StringBuilder();
-    private String groupId;
-
-    public Student(User user, String groupId) {
-        this.user = user;
-        this.groupId = groupId;
-    }
-
-    public User getUser() {
-        return user;
-    }
-
-    public void setUser(User user) {
-        this.user = user;
-    }
-
-    public StringBuilder getMarks() {
-        return marks;
-    }
-
-    public void setMarks(String marks) {
-        this.marks.append(marks);
-    }
-
-    public String getGroupId() {
-        return groupId;
-    }
-
-    public void setGroupId(String groupId) {
-        this.groupId = groupId;
-    }
-
-    @Override
-    public String toString() {
-        return "Student{" +
-                "user=" + user +
-                ", marks=" + marks +
-                ", groupId='" + groupId + '\'' +
-                '}';
-    }
-}
diff --git a/src/service/UserService.java b/src/service/UserService.java
new file mode 100644
index 0000000..998058e
--- /dev/null
+++ b/src/service/UserService.java
@@ -0,0 +1,6 @@
+package service;
+
+
+public class UserService {
+
+}