private void ReadData(string fileName)
        {
            string path = SessionData.currentPath + "\\" + fileName;

            if (File.Exists(path))
            {
                OutputWriter.WriteMessageOnNewLine("Reading data...");

                string   pattern       = @"([A-Z][a-zA-Z#\++]*_[A-Z][a-z]{2}_\d{4})\s+([A-Za-z]+\d{2}_\d{2,4})\s([\s0-9]+)";
                Regex    rgx           = new Regex(pattern);
                string[] allInputLines = File.ReadAllLines(path);

                for (int line = 0; line < allInputLines.Length; line++)
                {
                    if (!string.IsNullOrEmpty(allInputLines[line]) && rgx.IsMatch(allInputLines[line]))
                    {
                        Match  currentMatch = rgx.Match(allInputLines[line]);
                        string courseName   = currentMatch.Groups[1].Value;
                        string username     = currentMatch.Groups[2].Value;
                        string scoresStr    = currentMatch.Groups[3].Value;
                        try
                        {
                            int[] scores = scoresStr.Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries)
                                           .Select(int.Parse)
                                           .ToArray();

                            if (scores.Any(x => x > 100 || x < 0))
                            {
                                OutputWriter.DisplayException(ExceptionMessages.InvalidScore);
                                continue;
                            }

                            if (scores.Length > SoftUniCourse.NumberOfTasksOnExam)
                            {
                                OutputWriter.DisplayException(ExceptionMessages.InvalidNumberOfScores);
                                continue;
                            }

                            if (!this.Students.ContainsKey(username))
                            {
                                this.students.Add(username, new SoftUniStudent(username));
                            }

                            if (!this.Courses.ContainsKey(courseName))
                            {
                                this.courses.Add(courseName, new SoftUniCourse(courseName));
                            }

                            SoftUniCourse  course  = this.Courses[courseName];
                            SoftUniStudent student = this.Students[username];

                            student.EnrollInCourse(course);
                            student.SetMarkOnCourse(courseName, scores);

                            course.EnrollStudent(student);
                        }
                        catch (Exception ex)
                        {
                            OutputWriter.DisplayException(ex.Message + $"at line : {line}");
                        }
                    }
                }

                this.isDataInitialized = true;
                OutputWriter.WriteMessageOnNewLine("Data read!");
            }
            else
            {
                throw new InvalidPathException();
            }
        }