Java - Coding Challenge 1 - Speed Converter

gistfile1.txt

public class SpeedConverter {

    public static long toMilesPerHour(double kilometersPerHour){

        if (kilometersPerHour <0) {
            return -1;
        }

        return Math.round(kilometersPerHour/1.609);

    }

    public static void printConversion (double kilometersPerHour) {

        if (kilometersPerHour <0) {
            System.out.println("Invalid Value");
        } else {
            long mPH = toMilesPerHour(kilometersPerHour);
            System.out.println(kilometersPerHour + " km/h = " + mPH + " mi/h");
        }

    }

}

public class Main {
public static void main(String[] args) {

}

public static long toMilesPerHour(double kilometersPerHour) {
    if (kilometersPerHour < 0) {
        return -1;
    } else {
        return Math.round(kilometersPerHour / 1.609);
    }
}

public static void PrintConversion(double kilometersPerHour) {
    if (kilometersPerHour < 0) {
        System.out.println("print invalid value");
    } else {
        System.out.println(kilometersPerHour + "km/h   " + Math.round(kilometersPerHour / 1.609) + "mi/h ");
    }
}

}

yes first one is working now