public?class?HelloWorld?{
????public?static?void?main(String[]?args)?{
		//?創建一個空的StringBuilder對象
		StringBuilder?str?=?new?StringBuilder();
????????
		//?追加字符串
		str.append("jaewkjldfxmopzdm");
		
????????//?從后往前每隔三位插入逗號
????????for(int?i?=?str.length();i?>?0;i--){
????????????if(i%3?==?0){
????????????????str.insert(str.length()-i,",");
????????????}
????????}
????????
		
????????//?將StringBuilder對象轉換為String對象并輸出
		System.out.print(str.toString());
	}
}