Java 温度转换

import java.util.Scanner;
public class Main {
  public static int swap(int a)
 {
   double k;
   k = (a-32)*5/9.0;
  return (int)(k);
 }
 public static void  main(String[] args)
 {
  Scanner in = new Scanner(System.in);
  int a ;
  a = in.nextInt() ;
  System.out.println(swap(a));
 }
}