1395C - Boboniu Bit Operations

using namespace std;
using vi = vector<int>;
int n, m;
vi a, b;
bool possible(int mask)
{
    for (auto const &ai : a)
    {
        bool ok = false;
        for (auto const &bi : b)
        {
            if (((ai & bi) | mask) == mask)
            {
                ok = true;
                break;
            }
        }
        if (not ok)
            return false;
    }
    return true;
}
int solve(void)
{
    for (int mask = 0; mask < (1 << 9); ++mask)
    {
        if (possible(mask))
            return mask;
    }
    return (1 << 9) - 1;
}
int main(void)
{
    cin >> n >> m;
    a.resize(n);
    b.resize(m);
    for (auto &ai : a)
        cin >> ai;
    for (auto &bi : b)
        cin >> bi;
    cout << solve() << endl;
    return 0;
}