最后超时了

#include<iostream>
#include<cstring>
using namespace std;
bool zs[100000001];
void ZS(int b)
{
    memset(zs, true, sizeof(zs));
    {
        zs[1] = false;
        for (int i = 2; i * i <= b; i++)
        {
            if (zs[i])
            {
                for (int m = 2; m * i <= b; m++)
                {
                    zs[i * m] = false;
                }
            }
        }
    }
}
bool HWS(int n)
{
    int temp = n;
    int m = 0;
    while (temp != 0)
    {
        m = m * 10 + temp %10;
        temp/= 10;
    }
    if (m == n)
        return true;
    else return false;
}
int main()
{
    int a, b;
    cin >> a >> b;
    int i = a;
    ZS(b);
    if (i % 2 == 0)i++;
    if (a > b)return 0;
    if (b > 100000000)
    {
        b = 99999999;
    }
    for (i; i <= b; i++)
    {
        if (zs[i] && HWS(i))
        {
            cout << i << endl;
        }

    }
}