private void Mn_Click(object sender, RoutedEventArgs e)
        {
            Answer.Content = "Result: ";
            int    system   = Convert.ToInt32(sysnumList.SelectedItem);
            int    system_2 = Convert.ToInt32(sysnumList_2.SelectedItem);
            string num      = firstNum.Text;
            string num_2    = secondNum.Text;

            int           result    = SysNumMath.toDecimal(system, num) * SysNumMath.toDecimal(system_2, num_2);
            int           res_sys   = Convert.ToInt32(result_sysnumList.SelectedItem);
            List <string> arrResult = new List <string>();

            arrResult = SysNumMath.FromDecimal(result, res_sys);
            if (res_sys != 10)
            {
                for (int i = 0; i < arrResult.Count; i++)
                {
                    Answer.Content += arrResult[i];
                }
            }
            else
            {
                Answer.Content += Convert.ToString(result);
            }
        }
        void toTranslate_Click(object sender, RoutedEventArgs e)
        {
            translateResult.Content = "Result: ";
            if (inWhatSystem.Text == "10")
            {
                translateResult.Content += Convert.ToString(SysNumMath.toDecimal(Convert.ToInt32(sysnumList_3.Text), numForTrans.Text));
            }
            else if (sysnumList_3.Text == "10")
            {
                int num    = Convert.ToInt32(numForTrans.Text);
                int system = Convert.ToInt32(inWhatSystem.SelectedItem);

                List <string> fromDec = SysNumMath.FromDecimal(num, system);
                for (int i = 0; i < fromDec.Count; i++)
                {
                    translateResult.Content += fromDec[i];
                }
            }
            else if (inWhatSystem.Text != "10")
            {
                int           from_WhatSystem = (Convert.ToInt32(sysnumList_3.SelectedItem));
                string        num_ForTrans    = numForTrans.Text;
                int           in_WhatSystem   = (Convert.ToInt32(inWhatSystem.SelectedItem));
                List <string> newNum          = SysNumMath.transToOtherSys(from_WhatSystem, num_ForTrans, in_WhatSystem);
                for (int i = 0; i < newNum.Count; i++)
                {
                    translateResult.Content += newNum[i];
                }
            }
        }