int solve(const vector<int>& arr, int d) {
    deque<int> dQ;
    vector<int> slidingWindow;
    for (int i = 0; i < arr.size(); ++i) {
        if (!dQ.empty() and dQ.front() == i - d) dQ.pop_front();
        while (!dQ.empty() and arr[dQ.back()] <= arr[i]) dQ.pop_back();
        dQ.push_back(i);
        if (i >= d - 1) slidingWindow.push_back(arr[dQ.front()]);
    }
    return *min_element(slidingWindow.begin(), slidingWindow.end());
}