#include <iostream>
#include <cstring>
#include <cmath>
#define int long long
using namespace std;
int f(int n) {
    int sum = 0;
    while (n) {
        sum += n % 10ll;
        n /= 10ll;
    }
    return sum;
}
bool is_prime(int n) {
    if (n <= 1)
        return false;
    for (int i = 2; i * i <= n; i++)
        if (n % i == 0)
            return false;
    return true;
}

signed main() {
    int l, r;
    cin >> l >> r;
    int ans = 1;
    bool flag = false;
    for (int i = ceil(sqrt(l)); i * i <= r; i++) {
        int x = i * i;
        if (is_prime(f(x))) {
            ans = ans * x % 998244353;
            flag = true;
        }
    }
    if (!flag) 
        cout << 0 << endl;
    else cout << ans;
    return 0;
}

WA 40 pts 求助