//DoulOperator.java
class DoulOperator
{
    //類的main方法
	public static void main(String args[])
   	{
		int  a = 0;
       	int  b = 1;
          //計算a+b
          a +=b;
          System.out.println("a+b="+a);
          //計算a-b
          a-=b;
          System.out.println("a-b="+a);
  	}
}