#include <bits/stdc++.h>
using namespace std;

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int N; cin >> N;
    vector<int> P = {1};
    while(true){
        cout << "? " << P.size() << endl;
        for(int i=0; i<P.size(); i++){
            if(i) cout << " ";
            cout << P.at(i);
        }
        cout << endl;

        int a,b; cin >> a >> b;
        if(a == -1){cout << "! " << -1 << endl; break;}
        if(b == N){cout << "! " << a << endl; break;}
        P.push_back(b);
    }
}