#include <bits/stdc++.h>
using namespace std;
typedef pair<int, int> pii;
const int N = 2010;
vector<int> g[N];
inline vector<vector<int>> Split(int n) {
    set<pii> st;
    vector<int> order;
    vector<int> deg(n + 1);
    for (int i = 1; i <= n; ++i) {
        deg[i] = g[i].size();
        st.insert(pii(deg[i], i));
    }
    for (int i = 1; i <= n; ++i) {
        pii tp = *st.begin(); st.erase(st.begin());
        int x = tp.second;
        order.push_back(x);
        for (auto y : g[x]) if (deg[y] != -1) {
            st.erase(pii(deg[y], y));
            --deg[y];
            st.insert(pii(deg[y], y));
        }
        deg[x] = -1;
    }
    reverse(order.begin(), order.end());
    vector<int> bel(n + 1, -1);
    vector<int> vis(n);
    vector<vector<int>> ans;
    for (auto x : order) {
        for (auto y : g[x]) if (bel[y] != -1) {
            vis[bel[y]] = 1;
        }
        for (int i = 0; i < (int)ans.size(); ++i) if (!vis[i]) {
            bel[x] = i;
            break;
        }
        if (bel[x] == -1) bel[x] = ans.size(), ans.push_back({});
        ans[bel[x]].push_back(x);
        for (auto y : g[x]) if (bel[y] != -1) {
            vis[bel[y]] = 0;
        }
    }
    return ans;   
}
int main() {
    int n;
    scanf("%d", &n);
    for (int i = 2; i <= n; ++i) {
        vector<vector<int>> st = Split(i - 1);
        for (auto pts : st) {
            while (pts.size()) {
                printf("? %d %d ", (int)pts.size() + 1, i);
                for (auto x : pts) printf("%d ", x);
                puts(""); fflush(stdout);
                int u, v;
                scanf("%d%d", &u, &v);
                if (u == -1 && v == -1) break;
                int y = u ^ v ^ i;
                g[i].push_back(y); g[y].push_back(i);
                pts.erase(find(pts.begin(), pts.end(), y));
            }
        }
    }
    vector<pii> ans;
    for (int i = 1; i <= n; ++i) 
        for (auto j : g[i]) if (i < j)
            ans.push_back({i, j});
    printf("! %d\n", (int)ans.size());
    for (auto [x, y]: ans) printf("%d %d\n", x, y);
    fflush(stdout);
    return 0;
}