求助

#include <iostream> 
#include <cmath>
using namespace std;
bool IsPrime(long x) {
	for (long i = 2; i <= sqrt(x); i++) {
		if (x % i == 0)
			return false;
	}
	return true;
}
long backward(long c) {
	long s = 0;
		while (c > 0)
		{
			s = s * 10 + (c % 10);
			c/= 10;
		}
	return s;
}
int main(){
	long M, N;
	long x = 0;
	bool find;
	cin >> M>>N;
	long array[100000001] = { 0 };
	for (long i=M; i <=N; i++) {
		if (IsPrime(i) && IsPrime(backward(i))) {
			find = true;
			x += 1;
			array[x - 1] = i;
		}	
	}
	if (find) {
		for (long k = 0; k <= N - M - 1; k++) {
			cout << array[k] << ',';
		}
		cout << array[N - M];
	}
	else
		cout << "No";
	return 0;
}