자바 run()과 start() 의 관계

public class A extends Thread {
	int count = 0;
	public void run(){
	        System.out.println("run");
	synchronized (this) {
	        for(int i =0; i < 50 ; i++){
	               count = count + i;
	        }
	        }
	} 
}

public class Test {
	public static void main(String argv[]) {
        A a = new A();
        a.start();
        synchronized (a) {
               System.out.println("wating");
               try{
            	   a.wait();
               }catch(InterruptedException e){
               }
               System.out.println(a.count);
} }
}