convert from java to swift

Class 04: import java.util.Scanner; public class 004 { public static void main(String[] args) { int score; char grade; System.out.println ("Enter your score: "); Scanner keyboard = new Scanner (System.in); score = keyboard.nextInt (); keyboard.close(); if (score >= 90) grade = 'A'; else if (score >= 80) grade = 'B'; else if (score >= 70) grade = 'C'; else if (score >= 60) grade = ''; else grade = 'F'; System.out.println("Score = " + score); System.out.println ("Grade = " + grade); }