// see pg 85 and chap14.txt
// Some exceptions are CHECKED by the compiler. But, why? how?
// Some methods from Java API can easily make "mistakes"
// as in wrong input, doing illegal math, etc.
// So, many of these methods cause exceptions.
// In the hopes of creating code that won't crash, Java
// forces the programmer to handle these exceptions by making
// many of them CHECKED. If the compiler spots a method you have not
// provided checking using throws or catch, the compiler will complain.

import java.io.*; // need for I/O routines below

public class except4 {

    // The following code will contain readline() which MIGHT issue
    // an IOException. Two ways to handle exception:
    // 1st way: use a catch
    // 2nd way: have main "throw" the exception like throwing a
    //          "hot potato" out of the program

    // The "throws IOException" is the 2nd way
    // I left it out to show you how the compiler will gripe.

    /* The Excetption from the compiler:

       except4.java:35: Exception java.io.IOException must be caught,
       or it must be declared in the throws clause of this method.
       String temp = stdin.readLine();
				   ^
				   1 error
    */


    public static void main(String args[]) {

	// fix the mistake by saying:
	// public static void main(String args[]) throws IOException {
	
	// Alternative solution to HW1 follows.

	// initialize Text object in to read from standard input.
	BufferedReader stdin = new BufferedReader
	    (new InputStreamReader(System.in));
	
	// Read and write some numbers and strings
	System.out.println("Please enter an integer: ");
	
	// Read integer
	String temp = stdin.readLine();
	int k = Integer.parseInt(temp);
	
	// Perform algorithm
	while ( k > 1 )
	    if ( (k % 2 ) == 0) {     // test if k is even
		k = k / 2;
		System.out.println(k + " after dividing by 2");
	    }
	    else {
		k = 3 * k + 1;
		System.out.println(k + " after multiplying by 3 and adding 1");
	    }
	System.out.println("Done!");
    }
}