问如何修复“不是语句”？

EN

import java.util.*; // needed for Scanner class  
public class PhoneCalls   
{      
  public static void main (String[] args)         
  {        

    Scanner reader = new Scanner(System.in); // needed to read user input   
    System.out.println ("Enter the length of a phone call in minutues (an integer). ");
    int length=reader.nextInt();
    System.out.println ("Do you have a discount plan (answer 1 for yes and 2 for no):");
    int plan=reader.nextInt();
    (double) cost;
    if (length<=3 && plan==2)         
     (double) cost=.2*length; 
     else if (length<=3 && plan==1)
      (double) cost= 0.2*length*0.6;
     else if (length>3 && plan==2)
      (double) cost = (.2*3)+(.08*(length-3));
      else (double) cost = .2*3 + (.08*(length-3)* 0.6);                      
     System.out.println("The cost of your call is $ ");
     System.out.printf("%.2f.", cost);

  } 
}