文件目录

#include <iostream>
#include <cmath>
using namespace std;
bool isp(int n)
{
    if (n < 2)
        return 0;
    for (int i = 2; i <= sqrt(n); i++)
        if (n % i == 0)
            return 0;
    return 1;
}
int geth(int n)
{
    int m = 0;
    while (n)
    {
        m = m * 10 + n % 10;
        n /= 10;
    }
    return m;
}
int main()
{
    int m, n;
    cin >> m >> n;
    bool f = 1;
    for (int i = m; i <= n; i++)
    {
        if (isp(i) && isp(geth(i)))
        {
            if (f)
            {
                cout << i;
                f = 0;
            }
            else
                cout << "," << i;
        }
    }
    if (f)
        cout << "No";
    return 0;
}