//interactive
int ask(set<int>a,ll f=1){
    wt(f?'?':'!',(int)a.size());
    wt(a);
    return f?rd_ll():1;
}
{
    ll@N;
    set<int>a;
    rep(i,1,N+1)a.insert(i);
    rep(i,1,N+1){
        a.erase(i);
        if(!ask(a)) {
            a.insert(i);
        }
    }
    ask(a,0);
}