在DEV上编译测试通过，为什么这里不行QAQ

#include<iostream>
#include<cstring>
#include<cmath>
using namespace std;
bool array[10000001];

int esp(int b) {
	memset(array,true,sizeof(array));
	array[1] =array[0] = false;
	int n = sqrt(b);
	for(int step = 0; step <= n; step++) {
		if(array[step]) {
			for(int j = 2; j <= b/step; j++)
				array[step * j] = false;
		}
	}
}

bool hw(int b) {
	int temp = b,ans = 0;
	while(temp != 0) {
		ans=ans*10+temp%10;
		temp /= 10;
	}
	if(ans == b)return true;
	return false;
}

int main() {
	int a,b;
	cin>>a>>b;
	esp(b);
	if (a%2==0) a++;
	for (int i=a; i<=b; i+=2) {
		if (array[i] && hw(i))
			cout<<i<<endl;
	}
	return 0;
}