import java.io.*;

/** The <B>Console</B> class consists of static methods that allow easy reading 
    of the basic data types <TT>double</TT>, <TT>int</TT>, and <TT>String</TT> 
    from standard input. <I>It must be placed in the same directory containing 
    the source code using it.</I><P>

     <B>Usage Example:</B>
     <PRE>
     System.out.println("Enter a double number: ");
     double x = Console.readDouble();
      System.out.println("You have entered: " + x);
      </PRE>
 
      @author Bert G. Wachsmuth 
      @version 98/03/10
*/

public class Console
{
	/** Reads a single double value from the keyboard. If there is an error, the 
	    program will halt. 
	    @return double  
	*/
	public static double readDouble()
	{
		String tmpX = readString().trim();

		try
		{
			return (new Double(tmpX)).doubleValue();
		}
		catch (NumberFormatException ne)
		{
			System.err.println("Not a double. Quitting ...");
			System.exit(-1);
			return 0.0;
		}
	}

	/** Reads a single int value from the keyboard. If there is an error, the 
	    program will halt.
	    @return int 
	*/

	public static int readInt()
	{
		String tmpX = readString().trim();
		try
		{
			return Integer.parseInt(tmpX);
		}

		catch (NumberFormatException ne)
		{
			System.err.println("Not an integer. Quitting ...");
			System.exit(-1);
			return -1;
		}
	}

	/** Reads a String from the keyboard until RETURN or ENTER key is pressed. 
	    @return String 
	*/

	public static String readString()
	{
		String string = new String();
		try
		{
		    int cc = System.in.read();
			while (!((cc == 13) || (cc == 10)))
			{
				string += (char) cc;
				cc = System.in.read();
			}
		}
		catch (IOException e)
		{
		}
		return string;

	}
}