java多线程模拟火车站窗口卖票的问题

package com.cal;

public class TicketsThread {
public static void main(String[] args) {

T tt=new T();

Thread thread=new Thread(tt,"窗口1");
Thread thread2=new Thread(tt,"窗口2");
Thread thread3=new Thread(tt,"窗口3");

thread.start();
thread2.start();
thread3.start();
}
}

class T implements Runnable{
//总的票数
private int count=5;

@Override
public void run() {
synchronized (this) {
while(count>0){
count--;
System.out.println(Thread.currentThread().getName()+"卖了一张票,还剩下"+count+"张票");
}
}
}
}