稻花香里说丰年，听取WA声一片

#include<bits/stdc++.h>
using namespace std;
int n, m;
bool has = 0;
bool isprime(int n) {
	for (int i = 2; i * i <= n; i++) {
		if (!n % i)return 0;
	}
	return 1;
}
void trueprime(int n, int m) {
	for (int i = n; i <= m; i++) {
		string a = to_string(i);
		reverse(a.begin(), a.end());
		int di = stoi(a);
		if (isprime(i) && isprime(di)) {
			cout << i << ",";
			has = 1;
		}
	}
	return ;
}
int main() {
	cin >> n >> m;
	trueprime(n, m);
	if (!has)cout << "No";
	return 0;
}