int n = in.nextInt(); String s = in.next(); System.out.println(new StringBuffer(s).reverse().toString());
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 in = new Scanner(System.in);
int n = 0;
String s = "";
if (in.hasNextInt()) {
n = in.nextInt();
}
if (in.hasNext()) {
s = in.next();
}
char[] a = s.toCharArray();
for (int i=n-1;i>=0; i--){
System.out.print(a[i]);
}
}
}