为啥这会 Idleness limit exceeded

#include <cstdio>
#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
int n, k;
int query(int start,int end)
{
    int ans = 0, x;
    int mid = (start + end) / 2, rest = k - (end - start + 1) / 2;
    vector<int> temp;
    for (int i = 1; i <= n && rest;i++)
    {
        if(i>=start && i<=end)
            continue;
        rest--;
        temp.push_back(i);
    }
    cout << "?";
    for (int i = start; i <= mid;i++)
        cout << " " << i;
    for (int i = 0; i < temp.size();i++)
        cout << " " << temp[i];
    cout << endl;
    cin >> x;
    ans ^= x;
    cout << "?";
    for (int i = mid + 1; i <= end; i++)
        cout << " " << i;
    for (int i = 0; i < temp.size();i++)
        cout << " " << temp[i];
    cout << endl;
    cin >> x;
    ans ^= x;
    return ans;
}
int main()
{
    cin >> n >> k;
    if(n%2==1 && k%2==0)
    {
        cout << "-1";
        return 0;
    }
    int left = n % k;
    if(left%2==1)
        left += k;
    int ans = 0, x;
    for (int i = left + 1; i <= n; i += k)
    {
        cout << "?";
        for (int j = 1; j <= k;j++)
            cout << " " << i + j - 1;
        cout << endl;
        cin >> x;
        ans ^= x;
    }
    int place = 1;
    while(place<=left)
    {
        ans ^= query(place, min(place + 2 * k - 1, left));
        place += 2 * k;
    }
    cout << "! " << ans;
    return 0;
}