题解 | #数字颠倒#

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String in = sc.next();
        StringBuilder sb = new StringBuilder();
        for (int i = in.length() - 1; i >= 0; i--) {
            sb.append(in.charAt(i));
        }
        System.out.println(sb);
    }
}