题目

import java.util.Scanner;
public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		StringBuffer s = new StringBuffer();
		//字符串转为整型数
		if(n>0) {
			s.append(n);
			String ss = s.reverse().toString();
			int res = Integer.valueOf(ss);//
			System.out.println(res);
		}else if(n<0) {
			n = -n;
			s.append(n);
			String ss = s.reverse().toString();
			int res = Integer.valueOf(ss);//
			System.out.println(-res);			
		}else {
			System.out.println(n);//0
		}
	}
}