2-6编程总是报错

public class DisCountDemo {

    public double jg(double n){

        double a;

        if(n>=200){

            a=n*0.85;

        }else if(n<200&n>=100){

            a=n*0.95;

        }else{

            a=n;

        }

       return a； 

    }

       public static void main(String[] args) {

              double n2,n3;

              System.out.println("请输入价格：");

              Scanner sc=new Scanner(System.in);

              double n2=sc.nextDouble();

              DisCountDemo ad=new DisCountDemo();

              n3=ad.jg(n2);

             System.out.println("商品总价为"+n3);        

       }

}

报错：

DisCountDemo.java:20: error: cannot find symbol

               Scanner sc=new Scanner(System.in);

               ^

  symbol:   class Scanner

  location: class DisCountDemo

DisCountDemo.java:20: error: cannot find symbol

               Scanner sc=new Scanner(System.in);

                              ^

  symbol:   class Scanner

  location: class DisCountDemo

2 errors