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);
        long n = sc.nextLong();
        String strN = String.valueOf(n);
        char[] c = strN.toCharArray();
        StringBuilder sb = new StringBuilder();
        for(int i=c.length-1; i>=0; i--){
            sb.append(c[i]);
        }
        System.out.println(sb.toString());
    }
}