Metric Converter

import java.util.Scanner;

    public class MetricConverter {
        public static void main(String[] args) {
            Scanner scanner = new Scanner(System.in);

            double size = Double.parseDouble(scanner.nextLine());
            String sourceMetric = scanner.next().toLowerCase();
            String destMetric = scanner.next().toLowerCase();


            if (sourceMetric.equals("km")) {
                size = size / 0.001;
            } else if (sourceMetric.equals("mm")) {
                size = size / 1000;
            } else if (sourceMetric.equals("cm")) {
                size = size / 100;
            } else if (sourceMetric.equals("mi")) {
                size = size / 0.000621371192;
            } else if (sourceMetric.equals("in")) {
                size = size / 39.3700787;
            } else if (sourceMetric.equals("ft")) {
                size = size / 3.2808399;
            } else if (sourceMetric.equals("yd")) {
                size = size / 1.0936133;
            }


            if (destMetric.equals("km")) {
                size = size * 0.001;
            } else if (destMetric.equals("mm")) {
                size = size * 1000;
            } else if (destMetric.equals("cm")) {
                size = size * 100;
            } else if (destMetric.equals("mi")) {
                size = size * 0.000621371192;
            } else if (destMetric.equals("in")) {
                size = size * 39.3700787;
            } else if (destMetric.equals("ft")) {
                size = size * 3.2808399;
            } else if (destMetric.equals("yd")) {
                size = size * 1.0936133;
            }
            System.out.printf("%.8f %s", size, destMetric);
        }
    }