//package hello;     //must be in hello subdir, run: java hello.Hello
//import java.util.Date;     //deprecated
//import java.util.Calendar;
import java.util.*;

public  class Hello {                      
    //    static boolean not_first_call;

    //    public  static void main(String[] args) throws java.io.IOException{
    public  static void main(String[] args){
	//return;  //error: remaining code is unreachable

	/*
	//random unicode??   outputs ?  as single bytes
	System.out.println('\u01f0');   
	System.out.println('\u02f0');   
	System.out.println('\u03f0');   
	*/

	/*
	boolean b = true;
	System.out.println("b= "+b);   
	System.out.println('\u00f0');   
	*/
	//OA parsed first as literal linefeed!  cant even be commented!
	//	System.out.println("0A = "+'u000A'); //removed backslash!   
	/*
	char c;
	c = 651;
	System.out.println("c= "+c);   
	int i = 'a';
	System.out.println("i= "+i);   
	byte b1 = 120;
	System.out.println("b1= "+b1);   
	byte b2 = (byte)1000;
	System.out.println("b2= "+b2);   
	byte b3 = (byte)(b1 * 2);
	System.out.println("b3= "+b3);   
	*/

	/*
	System.out.println("Hello\n World!" +1234/23.0);   // / first
	String s = helloagain("asdfasdf");
	System.out.println(s);   
	System.out.println(args.length);   
	*/
	/*
	for (int i=0; i<args.length; i++)
	    System.out.println(args[i]);   
	*/
	/*
	System.out.println(" "+'\u0041'+'\u05D0');   //aleph
	System.out.println(" "+'\266'+'\273');   
	for (int i=32; i<256; i++)
	    System.out.print(Character.toString((char)i));
	*/
	//	System.out.println(System.getProperty("java.home"));   
	/*
	java.util.Properties sysprops = System.getProperties();
	sysprops.list(System.out);
	*/
	/*
	System.out.print("hello");   
	System.out.println("world");   
	*/
	/*
	char c$\u0041 = (char)System.in.read();
	System.out.println("char is " +c$\u0041);   
	*/

	/*
	System.out.println(3>2?1:1.3);   
	System.out.println(3>2?'e':1.3);   
	//	System.out.println(3>2?true:1);   //syntax error
	*/

	/*
	Hello hello_obj = new Hello();
	hello_obj.test();
	*/

	/*
	//	double inf = 1/0;
	double inf = 1./0;
	double neginf = -1./0;
	double negzero = -1/inf;
	double nan = 0./0;
	System.out.println("inf 1.0/0 = "+inf);   
	System.out.println("neginf -1.0/0 = "+neginf);   
	System.out.println("negzero -1/inf = "+negzero);   
	System.out.println("nan 0./0 = "+nan);   
	System.out.println("sqrt(-1) = "+Math.sqrt(-1));   

	if (nan == nan)
	    System.out.println("nan is nan");   
	else
	    System.out.println("nan is not nan");   
	if (Double.isNaN(nan))
	    System.out.println("nan is Double.isNan");   


	System.out.println("inf%2="+(inf%2));   
	//	System.out.println("3%0="+(3%0));     //syntax error
	System.out.println("-7%2="+(-7%2));   
	System.out.println("-7%-2="+(-7%-2));   
	System.out.println("4.3%2.1="+(4.3%2.1));   
	System.out.println("1-.1="+(1-.1));   
	*/
	/*
	float f1 = 1;
	//float f2 = 1.0;   //syntax error
	float f3 = 1F;
	float f4 = 1.0F;
	float f5 = (float)1.0;
	*/
	/*
	//int i = 0xffffffffffffffff;  	//integer literal too bit
	//int i = 0xfffffffff;  	//9 f's integer literal too big
	//int i2 = 0xffffffffffffffffL;  //loss of precision
	//long l1 = 0xffffffffffffffff;   //integer literal too bit
	long l2 = 0xffffffffffffffffL;
	int i = 0xffffffff;
	*/
	/*
	X x = new X(4);
	System.out.println(x.i);   
	x = new X();
	System.out.println(x.i);   
	*/
	/*
	X x = new X();     //Xi is 5
	Y y = new Y();     //Yi is 7, super's Xi is 5
	x.override();
	y.override();
	System.out.println(x.Xi);   
	//System.out.println(x.Yi);      //super doesn't have sub's field
	System.out.println(y.Xi);   
	System.out.println(y.Yi);   
	x = y;     //super = sub
	System.out.println(x.Xi);   
	//System.out.println(x.Yi);      //super doesn't have sub's field, even
	                           //if assigned a sub object reference
	System.out.println(((Y)x).Yi);  //casting to sub allows access

	System.out.println(x.same);   //is X's same field
	System.out.println(((Y)x).same);   //is sub Y's same field
	x.override();   //is sub's overridden method
	*/

	/*
	boolean b=true;
	char c='a';
	if (b == c)    //error
	    System.out.println("asdf");
	*/

	/*
	if (!not_first_call) {
	    not_first_call = true; 
	    W w = new W();
	    w.overridetest();
	    w.main(new String[]{"whats","up","doc"});
	}
	*/
	/*
	X x = new X();
	*/
	/*
	Y y = new Y();
	if (x.equals(y))
	    System.out.println("asdf");
	else
	    System.out.println("difffent type objects are always not equal");
	*/
	/*
	String s1;
	String s2="";
	if (s2.equals(s1))    //error, not initialized
	    System.out.println("asdf");
	else
	    System.out.println("empty string not the same as null");
	*/
	/*
	Date today = new Date();
	System.out.println(today.getMonth());
	System.out.println(today.getDay());
	System.out.println(today.getYear());
	Calendar now = Calendar.getInstance();
	System.out.println(now.get(Calendar.MONTH));
	*/
	/*
	try {
	    System.out.println("hi again inside try");
	}
	catch (Throwable e) {
	}
	*/
	/*
	String ups = "ABCD";
	String s = ups.toUpperCase();
	if (ups == s)
	    System.out.println("same refs");
	*/
	/*
	switch (2) {
	default: System.out.println("default");
	    break;
	case 3: System.out.println("case 3");
	    break;
	}
	*/
	/*
	int asdf;
	System.out.println("value of assignment expression: "+(asdf=5));
	*/
	/*
	System.out.println(3+4+" hi");
	System.out.println("Hi"+3+4);
	*/
	/*
	if ("dog" == "dog")
	    System.out.println("dog == dog");
	String d = "dog";
	if (d == "dog")     //true!
	    System.out.println("d == dog");
	String d2 = "dog";     //same object as d's dog?
	if (d == d2)     //true?!?!
	    System.out.println("d == d2");
	String d3 = new String("dog");
	if (d == d3)     //false.  new STring object
	    System.out.println("d == d3");
	if (d.equals(d2))     //true
	    System.out.println("d equals dog");

	if ('a' == 97)
	    System.out.println("a == 97");
	//if (5 == true)    //syntax error
	//  System.out.println("5 == true");
	//if (5 == "dog")    //syntax error
	//  System.out.println("5 == dog");
	*/
	/*
	X x = new X();
	if (x instanceof X)
	    System.out.println("x is an X");
	if (x instanceof Object)
	    System.out.println("x is an Object");
	//if (x instanceof String)    //syntax error
	//System.out.println("x is an String");
	*/
	/*
	X x = new X();
	System.out.println("x.xx= "+x.xx);
	System.out.println("X.xx= "+X.xx);
	X x2;
	//System.out.println("x2.xx= "+x2.xx);//syntax error because x2 uninit
	*/
	/*
	final int a=1;
	final int b;
	int arf=0;
	b = 2;    //not a constant, so can't be case value
	switch (arf) {
	case a: System.out.println("arf == a"); break;
	    //case b: System.out.println("arf == b"); break;
	}
	*/
	/*
	//compile with -source 1.4, else syntax erro, thinks is identifier
	//run with -ea to enable, else ignores
	//assert (false) : "its false";
	assert (false) : 5+11;
	*/
	/*
	int a = 10;
	int [][] M = new int[a][];
	System.out.println("M.lenght="+M.length);
	for (int i=0; i<a; i++) {
	    M[i] = new int[i+1];
	    for (int j=0; j<=i; j++)
		M[i][j] = i*j;
	}
	for (int i=0; i<a; i++) {
	    for (int j=0; j<=i; j++)
		System.out.print(M[i][j]+" ");
	    System.out.println();
	}
	*/
	/*
	X x = new X();
	System.out.println("x.Xi="+x.Xi);
	X x2 = new X(3);
	System.out.println("x2.Xi="+x2.Xi);
	*/
	/*
	X x = new X();
	Object o = new Object();
	o = x;
	X x2;
	x2 = (X)o;    //cast needed for compiler
	o = null;
	x2 = (X)o;    //cast needed for compiler
	Y y = new Y();
	System.out.println("Y.same="+y.same);
	o = y;
	System.out.println("o.same="+((Y)o).same);
	System.out.println("o.same="+((X)o).same);
	System.out.println("o.same="+((Y)o).Xi);
	System.out.println("o.same="+((X)o).Xi);
	*/
	/*
	Y y = new Y();
	y.superaccess();
	*/
	/*
	System.out.println(Math.ceil(9.2));
	System.out.println(Integer.MIN_VALUE);
	System.out.println(Math.abs(Integer.MIN_VALUE));
	*/
	/*
	System.out.println("round 4.5:  "+Math.round(4.5));
	System.out.println("round -4.5: "+Math.round(-4.5));
	System.out.println("round -4.2: "+Math.round(-4.2));
	System.out.println("round -4.8: "+Math.round(-4.8));
	System.out.println("floor 4.5:  "+Math.floor(4.5));
	System.out.println("floor -4.5: "+Math.floor(-4.5));
	System.out.println("floor -4.2: "+Math.floor(-4.2));
	System.out.println("floor -4.8: "+Math.floor(-4.8));
	System.out.println("ceil 4.5:  "+Math.ceil(4.5));
	System.out.println("ceil -4.5: "+Math.ceil(-4.5));
	System.out.println("ceil -4.2: "+Math.ceil(-4.2));
	System.out.println("ceil -4.8: "+Math.ceil(-4.8));
	*/
	/*
	System.out.println(Math.round());
	System.out.println(Math.round());
	System.out.println(Math.);
	System.out.println(Math.);
	System.out.println(Math.);
	System.out.println(Math.);
	System.out.println(Math.);
	System.out.println(Math.);
	*/

	/*
	//StringBuffer sb = "fred";  //syntax error
	StringBuffer sb = new StringBuffer("fred");  
	sb.append(543).append(true).reverse().insert(4,"ALF");
	System.out.println(sb);

	String s = new String("    alf");
	s = s.concat("bob").replace('a','#').toUpperCase().trim();
	System.out.println(s);
	*/

	//Math m = new Math();  //Math has private ctor, can't create instance
	/*
	Integer i1 = new Integer(42);
	Integer i2 = new Integer("42");
	Integer i3 = Integer.valueOf("42");
	Integer i4 = Integer.valueOf("2a",16);
	System.out.println(i1+"  "+i2);
	System.out.println(i3+"  "+i4);
	int i5 = i1.intValue();
	byte b5 = i1.byteValue();
	System.out.println(i5+"  "+b5);
	System.out.println(Integer.parseInt("42")+"  ");


	Character c1 = new Character('s');
	//Character c2 = new Character("s");   //ctor can't be String
	*/
	/*
	X x1 = new X();
	X x2 = new X();
	System.out.println(x1);   //default toString is hashcode
	System.out.println(x1.hashCode()); 
	if (x1 == x2)
	    System.out.println("two X's ==");
	else
	    System.out.println("two X's do not ==");
	if (x1.equals(x2))    //default Objcet equals() is same as ==
	    System.out.println("two X's equal");
	else
	    System.out.println("two X's do not equal");

	x1.Xi = 6;
	if (x1.equals(x2))    //default Objcet equals() is same as ==
	    System.out.println("two X's equal");
	else
	    System.out.println("two X's do not equal");
	*/
	/*
	Runtime rt = Runtime.getRuntime();
	System.out.println("total JVM memory: "+rt.totalMemory());
	System.out.println("free  JVM memory: "+rt.freeMemory());
	java.util.Date d;
	for (int i=0; i<100000; i++) {
	    d = new java.util.Date();
	    d = null;
	}
	System.out.println("free  JVM memory: "+rt.freeMemory());
	//rt.gc();
	System.gc();
	System.out.println("free  JVM memory: "+rt.freeMemory());
	*/

	/*
	java.util.Random rand;
	rand = new java.util.Random(System.currentTimeMillis());
	//in java.util.
	HashSet hs = new HashSet();
	LinkedHashSet lhs = new LinkedHashSet();
	TreeSet ts = new TreeSet();
	ArrayList al = new ArrayList();
	Vector vec = new Vector();
	LinkedList ll = new LinkedList();
	HashMap hm = new HashMap();
	Hashtable ht = new Hashtable();
	TreeMap tm = new TreeMap();
	LinkedHashMap lhm = new LinkedHashMap();

	for (int i=0; i<10; i++) {
	    Integer val = new Integer(rand.nextInt(10));
	    System.out.print(val+" ");
	    hs.add(val);
	    lhs.add(val);
	    ts.add(val);
	    al.add(val);
	    vec.add(val);
	    ll.add(val);			 
	    hm.put(val,val.toString());
	    ht.put(val,val.toString());
	    tm.put(val,val.toString());
	    lhm.put(val,val.toString());
	}
	System.out.println();
	System.out.println("HashSet");
	Iterator it = hs.iterator();
	while (it.hasNext())
	    System.out.print(it.next()+" ");
	System.out.println("\nLinkedHashSet");
	it = lhs.iterator();
	while (it.hasNext())
	    System.out.print(it.next()+" ");
	System.out.println("\nTreeSet");
	it = ts.iterator();
	while (it.hasNext())
	    System.out.print(it.next()+" ");
	System.out.println("\nArrayList");
	it = al.iterator();
	while (it.hasNext())
	    System.out.print(it.next()+" ");
	System.out.println("\nVector");
	it = vec.iterator();
	while (it.hasNext())
	    System.out.print(it.next()+" ");
	System.out.println("\nLinkedList");
	it = ll.iterator();
	while (it.hasNext())
	    System.out.print(it.next()+" ");
	*/
	/*
	System.out.println("before Thread.sleep()");
	try {
	    Thread.sleep(3000);
	}
	catch (InterruptedException e) {}
	System.out.println("after Thread.sleep()");
	*/

	/*
	System.out.println("thread.MIN_PRIORITY: "+ Thread.MIN_PRIORITY);
	System.out.println("thread.NORM_PRIORITY: "+ Thread.NORM_PRIORITY);
	System.out.println("thread.MAX_PRIORITY: "+ Thread.MAX_PRIORITY);
	*/

	//recursive ctors example:
	//	Foo f = new Foo();

	/*
	StringBuffer sb1 = new StringBuffer("Amit");
	StringBuffer sb2 = new StringBuffer("Amit");
	String ss1 = "Amit";
	System.out.println(sb1==sb2);         //false
	//STringBuffer does not override Object's equals which is same as ==:
	System.out.println(sb1.equals(sb2));  //false!
	System.out.println(sb1.equals(ss1));  //false!
	System.out.println(ss1.equals(sb1));  //false!
	//System.out.println(sb1==ss1);   //syntax error
	*/

	//see if abstract super's ctor called:
	//Concrete conc = new Concrete();    //yes

	/*
	ch\u0061r \u0061 = '\u0062';
	System.out.println("ch\u0061r \u0061 is "+\u0061);
	*/

	//    return 0;//if try to make int main, runtime error
    }                                       

    /*
    public static String helloagain(String arf) {
	System.out.println(arf);   
	return "bob";
    }

    public  void test() {
	if (this instanceof Hello)
	    System.out.println("is ");   
	else
	    System.out.println("isnt ");   
    }
    */

    final void f_override() {}  //try to override in subclass
    void f_override(float x) {}  //here's an overload
}                                         



class X {
    static int xx=3;
    int Xi=5;
    int same=5;

    int asdf;
    //    {for (int i=0; i<5; i++,System.out.println("in init block i="+i));}

    //    static    {for (int i=0; i<5; i++,System.out.println("in static init block i="+i));}

    /*
    int i;
    static int j;
    void f() {
	int i;    //can have local var with same name as instance field
	int j;    //or static field
	{
	    //   int i;  //error, already defined in f()
	}
	//for (int i=0; i<10; i++) ;  //ditto
	    
    }
    */
    X(int Xi) {
	System.out.println("int ctor");
	this.Xi = Xi;
    }
    X() {
	this(1);    //if present, must be first statement in ctor
	System.out.println("default ctor");

	//i = 3;   //OK. i will get default value of 0
	//return;  //legal to have return as long as nothing returned
    }
    /*
    X(int m) {  //default ctor won't exist if any other ctor exists
	i = m;  //commenting out about ctor makes error to instantiate with X()
    }
    */
    void override() {
	System.out.println("in X's override");
    }
    public String toString() {    //override Object toString
	return "hello Im an X object.  nice to meet you: " + xx;
    }
    public boolean equals(Object o) {
	if ((o instanceof X) && (((X)o).Xi == this.Xi))
	    return true;
	else
	    return false;
    }

}

class Y extends X {
    int Yi=7;
    int same=7;
    Y() {
	super(12);
    }
    void superaccess() {
	System.out.println("Y.same="+same);
	System.out.println("super.same="+super.same);
	System.out.println("((X)this).same="+((X)this).same);
    }
    void override() {
	System.out.println("in Y's override");
    }
}



class W extends Hello {
    void overridetest() {
	int W;   //variable same name as class
	int override;   //variable same name as method
	this.main(new String[]{"cat","dog"});     //super's main
	super.main(new String[]{"meow","arf"});   //super's main
    }
    public static void main(String[] myargs) {
	//static int a;   //no static local vars
	int fint;
	System.out.println("overridden main");
    }
    int W;   //variable same name as class
    int override;   //variable same name as method

    //void f_override() {}   //attempt overrirde of final method in super
    void f_override(int i) {}  //an overload 
}


//can't be any other public class or interface
//default is ok
//public interface I {}


/*
class Foo {
    Foo() {
	//this();   //detects recursive ctor syntax error
	this("arf"); //but doesn't this mutually recursive which blows stack
    }
    Foo (String s) {
	this();
    }
}
*/

/*
abstract class Abs {
    Abs() {System.out.println("hi from Abs ctor");}
}
class Concrete extends Abs {
    Concrete() {System.out.println("hi from Concrete ctor");}
}
*/