解法一：进制转换+数学

主要实现两个小功能：进制转换并翻转，判断是否为素数。

import java.io.*;
import java.util.*;
public class Main {
    public static void main(String[] args) throws IOException {
        StreamTokenizer in = new StreamTokenizer(new BufferedReader(new InputStreamReader(System.in)));
        PrintWriter out = new PrintWriter(new OutputStreamWriter(System.out));
        while (true) {
            in.nextToken();
            int N = (int) in.nval;
            if (N < 0) {
                break;
            }
            in.nextToken();
            int radix = (int) in.nval;
            int reverse = reverse(N, radix);
            if (isPrime(N) && isPrime(reverse)) {
                out.println("Yes");
            } else {
                out.println("No");
            }
        }
        out.flush();
    }
    private static int reverse(int N, int radix) {
        String s = new StringBuilder(Integer.toString(N, radix)).reverse().toString();
        return Integer.parseInt(s, radix);
    }
    private static boolean isPrime(int N) {
        if (N <= 1) {
            return false;
        }
        boolean flag = true;
        for (int i = 2; i <= Math.sqrt(N); ++i) {
            if (N % i == 0) {
                flag = false;
                break;
            }
        }
        return flag;
    }
}