I want to calculate total number of "present" word occurances in datagridview

ClsConnection.Conn.Open();
            string sql_student = string.Format("select ADD_No, FName+' '+LName as Name from ADD_Master where ADD_No IN (select Student_Id from tbstudent_batchmaster where Batch_Identity=" + batchid + ")");
            SqlCommand cmd_stud = new SqlCommand(sql_student, ClsConnection.Conn);
            SqlDataReader stud_read = cmd_stud.ExecuteReader(CommandBehavior.CloseConnection);
            int rowcount = 0,totalpresent=0;
            while (stud_read.Read())
            {
                DataRow workRow = dt.NewRow();
                
                
                //dt.Rows.Add(stud_read[1].ToString());    
                workRow[0] = stud_read[1].ToString();
                for(int i=0;i<dates.Count;i++)
                {   
                    string sql_stud_att = "select student_id from tbbatch_att where student_id= " + stud_read[0] + " and batch_id=" + batchid + " and attendance_date='"+dates[i]+"'";
                    ClsConnection.Conn_repeat.Close();
                    ClsConnection.Conn_repeat.Open();
                    SqlCommand cmd_stud_att = new SqlCommand(sql_stud_att, ClsConnection.Conn_repeat);
                    SqlDataReader stud_read_att = cmd_stud_att.ExecuteReader(CommandBehavior.CloseConnection);
                    if (stud_read_att.HasRows)
                    {
                        //dt.Rows.Add("Present");
                        workRow[(i+1)] = "Present";
                        totalpresent++;
                    }
                    else
                    {
                        //dt.Rows.Add("Absent");
                        workRow[(i + 1)] = "Absent";
                    }
                    ClsConnection.Conn_repeat.Close();
                }
                
                dt.Rows.Add(workRow);
               
                rowcount++;
            }

            ClsConnection.Conn.Close();