---

using Avalonia.Controls;
using Avalonia.Interactivity;

namespace mishdimAAA
{
    public partial class MainWindow : Window
    {
        private string a = "";
        private string b = "";
        private string op = "";

        public MainWindow()
        {
            InitializeComponent();
        }

        // --- ЦИФРЫ ---

        private void Btn0_Click(object sender, RoutedEventArgs e)
        {
            if (op == "") { a += "0"; Display.Text = a; }
            else { b += "0"; Display.Text = b; }
        }

        private void Btn1_Click(object sender, RoutedEventArgs e)
        {
            if (op == "") { a += "1"; Display.Text = a; }
            else { b += "1"; Display.Text = b; }
        }

        private void Btn2_Click(object sender, RoutedEventArgs e)
        {
            if (op == "") { a += "2"; Display.Text = a; }
            else { b += "2"; Display.Text = b; }
        }

        private void Btn3_Click(object sender, RoutedEventArgs e)
        {
            if (op == "") { a += "3"; Display.Text = a; }
            else { b += "3"; Display.Text = b; }
        }

        private void Btn4_Click(object sender, RoutedEventArgs e)
        {
            if (op == "") { a += "4"; Display.Text = a; }
            else { b += "4"; Display.Text = b; }
        }

        private void Btn5_Click(object sender, RoutedEventArgs e)
        {
            if (op == "") { a += "5"; Display.Text = a; }
            else { b += "5"; Display.Text = b; }
        }

        private void Btn6_Click(object sender, RoutedEventArgs e)
        {
            if (op == "") { a += "6"; Display.Text = a; }
            else { b += "6"; Display.Text = b; }
        }

        private void Btn7_Click(object sender, RoutedEventArgs e)
        {
            if (op == "") { a += "7"; Display.Text = a; }
            else { b += "7"; Display.Text = b; }
        }

        private void Btn8_Click(object sender, RoutedEventArgs e)
        {
            if (op == "") { a += "8"; Display.Text = a; }
            else { b += "8"; Display.Text = b; }
        }

        private void Btn9_Click(object sender, RoutedEventArgs e)
        {
            if (op == "") { a += "9"; Display.Text = a; }
            else { b += "9"; Display.Text = b; }
        }

        // --- ОПЕРАЦИИ ---

        private void BtnPlus_Click(object sender, RoutedEventArgs e) { op = "+"; }
        private void BtnMinus_Click(object sender, RoutedEventArgs e) { op = "-"; }
        private void BtnMultiply_Click(object sender, RoutedEventArgs e) { op = "*"; }
        private void BtnDivide_Click(object sender, RoutedEventArgs e) { op = "/"; }

        // --- РАВНО ---

        private void BtnEquals_Click(object sender, RoutedEventArgs e)
        {
            if (double.TryParse(a, out double num1) && double.TryParse(b, out double num2))
            {
                double res = 0;

                if (op == "+") res = num1 + num2;
                if (op == "-") res = num1 - num2;
                if (op == "*") res = num1 * num2;
                if (op == "/") res = num2 != 0 ? num1 / num2 : 0;

                Display.Text = res.ToString();
                a = res.ToString();
                b = "";
                op = "";
            }
        }

        // --- СБРОС ---

        private void BtnClear_Click(object sender, RoutedEventArgs e)
        {
            a = "";
            b = "";
            op = "";
            Display.Text = "0";
        }
    }
}