请问这个代码应该如何写，完全没有思路啊，求解

这个怎么写代码啊，一点思路都没有，怎么办啊，求解⋯⋯⋯⋯⋯⋯⋯⋯

借鉴一下，改改。
public static void main(String[] args) {
// TODO Auto-generated method stub
Runtime runtime = Runtime.getRuntime();
System.out.println("占用内存："
+ (runtime.totalMemory() - runtime.freeMemory()));
long timeStamp = System.currentTimeMillis();
Scanner scanner = new Scanner(System.in);
while (scanner.hasNextInt()) {
int tem = scanner.nextInt();
System.out.println("输入的华氏温度是：" + tem);
Integer temperature = (tem - 32) * 5 / 9;
System.out.println("输出的摄氏温度是：" + temperature);
System.out.println("消耗时间（包含输入）："
+ (System.currentTimeMillis() - timeStamp) + "毫秒");
}
scanner.close();
}

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Test {
private static int F;
public static void main(String[] args) {

    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    try {
        F = Integer.parseInt(br.readLine());
    } catch (NumberFormatException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        if(br != null) {
            try {
                br.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }   
    System.out.println((int)((F-32)*5/9));
}

}