import java.util.Scanner;

/**
 * Temperature Converter (Java Version)
 * Supports conversion between Celsius (C) and Fahrenheit (F).
 *
 * Features:
 * 1. Interactive input, for example: 36.6 C or 97 F
 * 2. Command-line argument mode, for example:
 *    java TemperatureConverter 36.6 C
 */
public class TemperatureConverter {

    /**
     * Converts Celsius to Fahrenheit.
     *
     * @param c temperature in Celsius
     * @return equivalent temperature in Fahrenheit
     */
    public static double celsiusToFahrenheit(double c) {
        return c * 9.0 / 5.0 + 32.0;
    }

    /**
     * Converts Fahrenheit to Celsius.
     *
     * @param f temperature in Fahrenheit
     * @return equivalent temperature in Celsius
     */
    public static double fahrenheitToCelsius(double f) {
        return (f - 32.0) * 5.0 / 9.0;
    }

    /**
     * Main method of the program.
     *
     * Input examples:
     * 1. Interactive mode: 36.6 C
     * 2. Command-line mode: java TemperatureConverter 36.6 C
     *
     * @param args command-line arguments
     */
    public static void main(String[] args) {
        String input;

        // If command-line arguments are provided, use them first
        if (args.length > 0) {
            StringBuilder sb = new StringBuilder();
            for (String arg : args) {
                sb.append(arg).append(" ");
            }
            input = sb.toString().trim();
        } else {
            // Prompt the user for input, for example: "36.6 C" or "97 F"
            Scanner scanner = new Scanner(System.in);
            System.out.print("Enter the temperature and unit to convert (for example 36.6 C or 97 F): ");
            input = scanner.nextLine().trim();
        }

        if (input.isEmpty()) {
            System.out.println("Input is empty. Program terminated.");
            return;
        }

        String[] parts = input.split("\\s+");
        double value;
        String unit;

        try {
            // Allow the user to enter a numeric value and a unit
            value = Double.parseDouble(parts[0]);
            unit = (parts.length > 1) ? parts[1].toUpperCase() : "C";
        } catch (Exception e) {
            System.out.println("Failed to parse input. Please enter a value and unit like: 36.6 C");
            return;
        }

        if (unit.startsWith("C")) {
            // Convert from Celsius to Fahrenheit
            double f = celsiusToFahrenheit(value);
            System.out.printf("%.1f °C = %.2f °F%n", value, f);
        } else if (unit.startsWith("F")) {
            // Convert from Fahrenheit to Celsius
            double c = fahrenheitToCelsius(value);
            System.out.printf("%.1f °F = %.2f °C%n", value, c);
        } else {
            System.out.println("Unknown unit. Please use C or F.");
        }
    }
}