diff --git a/system.java b/system.java
new file mode 100644
index 0000000..ef3b330
--- /dev/null
+++ b/system.java
@@ -0,0 +1,110 @@
+   package java6201.lesson03;
+
+   import javafx.application.Application;
+   import javafx.geometry.Insets;
+   import javafx.geometry.Pos;
+   import javafx.scene.Scene;
+   import javafx.scene.control.Alert;
+   import javafx.scene.control.Alert.AlertType;
+   import javafx.scene.control.Button;
+   import javafx.scene.control.Label;
+   import javafx.scene.control.TextField;
+   import javafx.scene.layout.GridPane;
+   import javafx.stage.Stage;
+
+   public class system extends Application {
+
+       private TextField inputTextField;
+       private TextField sourceBaseTextField;
+       private TextField targetBaseTextField;
+       private Label resultLabel;
+
+       @Override
+       public void start(Stage primaryStage) {
+           primaryStage.setTitle("Base Converter");
+
+           GridPane grid = new GridPane();
+           grid.setAlignment(Pos.CENTER);
+           grid.setPadding(new Insets(10));
+           grid.setVgap(8);
+           grid.setHgap(10);
+
+           Label inputLabel = new Label("Input Number:");
+           inputTextField = new TextField();
+
+           Label sourceBaseLabel = new Label("Source Base (2-16):");
+           sourceBaseTextField = new TextField();
+           sourceBaseTextField.setText("10"); // Default to decimal
+
+           Label targetBaseLabel = new Label("Target Base (2-16):");
+           targetBaseTextField = new TextField();
+           targetBaseTextField.setText("2"); // Default to binary
+
+           Button convertButton = new Button("Convert");
+           resultLabel = new Label();
+
+           grid.add(inputLabel, 0, 0);
+           grid.add(inputTextField, 1, 0);
+           grid.add(sourceBaseLabel, 0, 1);
+           grid.add(sourceBaseTextField, 1, 1);
+           grid.add(targetBaseLabel, 0, 2);
+           grid.add(targetBaseTextField, 1, 2);
+           grid.add(convertButton, 1, 3);
+           grid.add(resultLabel, 1, 4);
+
+           convertButton.setOnAction(event -> convert());
+
+           Scene scene = new Scene(grid, 300, 200);
+           primaryStage.setScene(scene);
+           primaryStage.show();
+       }
+
+       private void convert() {
+           String input = inputTextField.getText();
+           String sourceBaseStr = sourceBaseTextField.getText();
+           String targetBaseStr = targetBaseTextField.getText();
+
+           try {
+               int sourceBase = Integer.parseInt(sourceBaseStr);
+               int targetBase = Integer.parseInt(targetBaseStr);
+
+               if (sourceBase < 2 || sourceBase > 16 || targetBase < 2 || targetBase > 16) {
+                   throw new IllegalArgumentException("Base must be between 2 and 16.");
+               }
+
+               long number = Long.parseLong(input, sourceBase);
+               String result = convertToBase(number, targetBase);
+
+               resultLabel.setText("Result: " + result);
+           } catch (NumberFormatException e) {
+               showAlert(AlertType.ERROR, "Invalid Input", "Number format error: " + e.getMessage());
+           } catch (IllegalArgumentException e) {
+               showAlert(AlertType.ERROR, "Invalid Input", "Illegal argument: " + e.getMessage());
+           }
+       }
+
+       private String convertToBase(long number, int base) {
+           if (number == 0) {
+               return "0";
+           }
+           StringBuilder result = new StringBuilder();
+           char[] digits = "0123456789ABCDEF".toCharArray();
+           while (number > 0) {
+               result.insert(0, digits[(int) (number % base)]);
+               number /= base;
+           }
+           return result.toString();
+       }
+
+       private void showAlert(AlertType alertType, String title, String content) {
+           Alert alert = new Alert(alertType);
+           alert.setTitle(title);
+           alert.setContentText(content);
+           alert.setHeaderText(null);
+           alert.showAndWait();
+       }
+
+       public static void main(String[] args) {
+           launch(args);
+       }
+   }