Watch

public class Watch
{
    public static void main(String []args)
    {
        for(int i = 0; i < 24; i++)
        {
            for (int j = 0; j < 60; j++)
            {
                for(int h = 0; h < 60; h++)
                {
                    System.out.println(i + " : " + j + " : " + h);
                }
            }
        }
        System.out.println("00 : 00 : 00");
    }
}