import javafx.application.Application;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;

public class GCDCalculator extends Application {

    @Override
    public void start(Stage primaryStage) {
        TextField num1Field = new TextField();
        num1Field.setPromptText("Enter first number");
        TextField num2Field = new TextField();
        num2Field.setPromptText("Enter second number");

        Label resultLabel = new Label();
        Button calculateButton = new Button("Calculate GCD");

        calculateButton.setOnAction(e -> {
            try {
                int num1 = Integer.parseInt(num1Field.getText());
                int num2 = Integer.parseInt(num2Field.getText());

                if (num1 <= 0 || num2 <= 0) {
                    resultLabel.setText("Please enter positive integers only");
                    return;
                }

                int gcd = calculateGCD(num1, num2);
                resultLabel.setText(
                    String.format("GCD of %d and %d is: %d", num1, num2, gcd)
                );
            } catch (NumberFormatException ex) {
                resultLabel.setText("Please enter valid integers");
            }
        });

        VBox root = new VBox(10);
        root.setAlignment(Pos.CENTER);
        root
            .getChildren()
            .addAll(num1Field, num2Field, calculateButton, resultLabel);

        Scene scene = new Scene(root, 300, 200);
        primaryStage.setTitle("GCD Calculator");
        primaryStage.setScene(scene);
        primaryStage.show();
    }

    private int calculateGCD(int a, int b) {
        while (b != 0) {
            int temp = b;
            b = a % b;
            a = temp;
        }
        return a;
    }

    public static void main(String[] args) {
        launch(args);
    }
}