if else แบบนี้ สามารถเปลี่ยนเป็น switch case ได้ไหมครับ

import java.util.*;
class ass1
{
 public static void main(String arg[])
 {
  int fi,mi,sc;
  
  System.out.print("Enter Final = ");
  Scanner a = new Scanner(System.in);
  fi = a.nextInt();
  if((fi>50)||(fi<0))System.exit(0);
  
  System.out.print("Enter Midterm = ");
  a = new Scanner(System.in);
  mi = a.nextInt();
  if((mi>30)||(mi<0))System.exit(0);
  
  System.out.print("Enter Score = ");
  a = new Scanner(System.in);
  sc = a.nextInt();
  if((sc>20)||(sc<0))System.exit(0);
 
  int sum = fi+mi+sc;
  System.out.println("Total = "+sum);
 
  if((sum>80)&&(sum<100))
   System.out.print("Grade A");
  else if((sum>70)&&(sum<79))
   System.out.print("Grade B");
  else if((sum>60)&&(sum<69))
   System.out.print("Grade C");
  else if((sum>50)&&(sum<59))
   System.out.print("Grade D");
  else
   System.out.print("Grade F"); 
 }}