Stuff

import java.util.*;public class Example2_18{	static Scanner console = new Scanner(System.in);    public static void main(String[] args)    {		int firstNum, secondNum;		char ch;		double z;		firstNum = 4;                                      		//Line 1		System.out.println("Line 2: firstNum = "		                  + firstNum);                     		//Line 2		secondNum = 2 * firstNum + 6;                      		//Line 3		System.out.println("Line 4: firstNum = " + firstNum		                 + ", secondNum = " + secondNum);  		//Line 4		z = (firstNum + 1) / 2.0;                          		//Line 5		System.out.println("Line 6: firstNum = " + firstNum		                 + ", secondNum = " + secondNum		                 + ", z = " + z);                  		//Line 6		ch = 'A';                                         		//Line 7		System.out.println("Line 8: firstNum = " + firstNum				         + ", secondNum = " + secondNum				         + ", ch = " + ch		                 + ", z = " + z);                 		//Line 8		secondNum = console.nextInt();                    		//Line 9		System.out.println("Line 10: firstNum = " + firstNum		     	         + ", secondNum = " + secondNum					     + ", ch = " + ch				         + ", z = " + z);                  		//Line 10		z = console.nextDouble();                         		//Line 11		System.out.println("Line 12: firstNum = " + firstNum				     	 + ", secondNum = " + secondNum						 + ", ch = " + ch				         + ", z = " + z);                  		//Line 12		firstNum = 2 * secondNum + (int)(z);              		//Line 13		System.out.println("Line 14: firstNum = " + firstNum				         + ", secondNum = " + secondNum						 + ", ch = " + ch				         + ", z = " + z);                  		//Line 14		secondNum = secondNum + 1;                       		//Line 15		System.out.println("Line 16: firstNum = " + firstNum				     	 + ", secondNum = " + secondNum						 + ", ch = " + ch				         + ", z = " + z);                  		//Line 16		ch = console.next().charAt(0);                   		//Line 17		System.out.println("Line 18: firstNum = " + firstNum				     	 + ", secondNum = " + secondNum						 + ", ch = " + ch				         + ", z = " + z);                  		//Line 18		firstNum = firstNum + (int)(ch);                 		//Line 19		System.out.println("Line 20: firstNum = " + firstNum				         + ", secondNum = " + secondNum						 + ", ch = " + ch				         + ", z = " + z);                  		//Line 20		z = firstNum - z;                                  		//Line 21		System.out.println("Line 22: firstNum = " + firstNum				         + ", secondNum = " + secondNum					     + ", ch = " + ch				         + ", z = " + z);                  		//Line 22    }}$ java Example2_18.classException in thread "main" java.lang.NoClassDefFoundError: Example2_18.class   at gnu.java.lang.MainThread.run() (/usr/lib/libgcj.so.6.0.0)Caused by: java.lang.ClassNotFoundException: Example2_18.class not found in gnu.gcj.runtime.SystemClassLoader{urls=[file:./,file:./], parent=gnu.gcj.runtime.ExtensionClassLoader{urls=[], parent=null}}   at java.net.URLClassLoader.findClass(java.lang.String) (/usr/lib/libgcj.so.6.0.0)   at java.lang.ClassLoader.loadClass(java.lang.String, boolean) (/usr/lib/libgcj.so.6.0.0)   at java.lang.ClassLoader.loadClass(java.lang.String) (/usr/lib/libgcj.so.6.0.0)   at java.lang.Class.forName(java.lang.String, boolean, java.lang.ClassLoader) (/usr/lib/libgcj.so.6.0.0)   at gnu.java.lang.MainThread.run() (/usr/lib/libgcj.so.6.0.0)