라인 이해

package theard;

public class MyThread extends Thread  
 {  
	int count= 1, number;  
	
	public MyThread(int num)  
	 {  
		number = num;  
		System.out.println("     " + number);  
	 }  
	 public void run() 
	 {  
		 while(true) 
		 {  
			 System.out.println ("   " + number + ":   " + count);
			 if(++count== 6) return;  
		 }  
	 }  
	 
	 public static void main(String args[])  
	 {  
		 /*for(int i = 0;  i < 5; i++)
		 {	 
			 new MyThread(i+1).start();  
		 }*/
		 
		 new MyThread(1).start();
		 new MyThread(2).start();
	 }  
 } //end class