#include <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) begin(v),end(v)
#define fi first
#define se second
template<typename A, typename B> inline bool chmax(A &a, B b) { if (a<b) { a=b; return 1; } return 0; }
template<typename A, typename B> inline bool chmin(A &a, B b) { if (a>b) { a=b; return 1; } return 0; }
using ll = long long;
using pii = pair<int, int>;
constexpr ll INF = 1ll<<30;
constexpr ll longINF = 1ll<<60;
constexpr ll MOD = 1000000007;
constexpr bool debug = 0;
//---------------------------------//

bool ans[1123];

int main() {
	int N;
	cin >> N;
	
	memset(ans, -1, sizeof(ans));
	REP(i, N) {
		ans[i] = 0;
		vector<int> query;
		REP(j, N) if (ans[j]) query.push_back(j + 1);
		
		printf("? %d\n", query.size());
		int res;
		REP(j, query.size()) printf("%d%c", query[j], j == query.size() - 1 ? '\n' : ' ');
		fflush(stdout);
		scanf("%d", &res);
		if (res == 0) ans[i] = 1;
		
		if (query.size() == 2 && res == 1) break;
	}
	
	vector<int> ansv;
	REP(i, N) if (ans[i]) ansv.push_back(i + 1);
	printf("! %d\n", ansv.size());
	REP(i, ansv.size()) printf("%d%c", ansv[i], i == ansv.size() - 1 ? '\n' : ' ');
	fflush(stdout);
	
	return 0;
}