private void Groups_SelectedIndexChanged(object sender, EventArgs e)
{
StudentsData.Rows.Clear();
var info = new GetInfo();
foreach (StudentInfo student in info.GetStudentInformationList(Groups.Text))
{
StudentsData.Rows.Add(student.Surname, student.RoundedMark, student.NoAttistation);
}
var roundedExems = info.GetExemsOnGroup(Groups.Text);
D1.Text = roundedExems[0].ToString();
D2.Text = roundedExems[1].ToString();
D3.Text = roundedExems[2].ToString();
D4.Text = roundedExems[3].ToString();
D5.Text = roundedExems[4].ToString();
debtors.Text = info.GetDebtorsCount(Groups.Text).ToString();
}