func_code_string: #include <bits/stdc++.h>   using namespace std;   const int MAXN = 610;   int N;   vector<int> edge[MAXN];   bool seen[MAXN];   int mtype[MAXN];   int par[MAXN];   int get_count(vector<int> v) {     if (v.size() <= 1) return 0;     cout <<  ?   << v.size() <<   n ;     for (int i = 0; i < v.size(); i++) {       if (i) cout <<    ;       cout << v[i] + 1;     }     cout <<   n  << flush;     int r;     cin >> r;     return r;   }   int through(vector<int> v, int cloc) {     int l = get_count(v);     v.push_back(cloc);     int r = get_count(v);     v.pop_back();     return r - l;   }   vector<int> find_all(vector<int> v, int cloc, int ntot) {     vector<int> res;     if (!ntot) return res;     if (ntot == v.size()) {       for (int x : v) res.push_back(x);       return res;     }     vector<int> vleft, vright;     for (int i = 0; i < v.size(); i++) {       if (i % 2 == 0)         vleft.push_back(v[i]);       else         vright.push_back(v[i]);     }     int tnew = through(vleft, cloc);     res = find_all(vleft, cloc, tnew);     vector<int> vres = find_all(vright, cloc, ntot - tnew);     for (int x : vres) res.push_back(x);     return res;   }   void bflood(int x) {     for (int neigh : edge[x]) {       if (par[neigh] == -1) {         par[neigh] = x;         bflood(neigh);       }     }   }   void solve_bad(int l, int r) {     for (int i = 0; i < MAXN; i++) par[i] = -1;     par[l] = l;     bflood(l);     vector<int> res;     int cloc = r;     while (cloc != l) {       res.push_back(cloc);       cloc = par[cloc];     }     res.push_back(cloc);     cout <<  N   << res.size() <<   n ;     for (int i = 0; i < res.size(); i++) {       if (i) cout <<    ;       cout << res[i] + 1;     }     cout << endl;   }   void wrong(vector<int> v) {     int vtot = get_count(v);     while (true) {       int cloc = v.back();       v.pop_back();       if (get_count(v) != vtot) {         for (int i = 0; i < v.size(); i++) {           vector<int> vq;           vq.push_back(cloc);           vq.push_back(v[i]);           if (get_count(vq)) {             solve_bad(cloc, v[i]);             return;           }         }       }     }   }   void dfs(int cloc) {     seen[cloc] = true;     vector<int> vposs;     for (int i = 0; i < N; i++)       if (cloc != i && !edge[i].size()) vposs.push_back(i);     vector<int> bv = find_all(vposs, cloc, through(vposs, cloc));     for (int i = 0; i < bv.size(); i++) {       edge[cloc].push_back(bv[i]);       edge[bv[i]].push_back(cloc);     }     for (int i = 0; i < bv.size(); i++) {       int neigh = bv[i];       if (!seen[neigh]) dfs(neigh);     }   }   void flood(int cloc, int ctype) {     mtype[cloc] = ctype;     for (int neigh : edge[cloc]) {       if (!mtype[neigh]) flood(neigh, 3 - ctype);     }   }   int main() {     ios_base::sync_with_stdio(0);     cin >> N;     dfs(0);     flood(0, 1);     vector<int> v1, v2;     for (int i = 0; i < N; i++) {       if (mtype[i] == 1)         v1.push_back(i);       else         v2.push_back(i);     }     if (get_count(v1) > 0)       wrong(v1);     else if (get_count(v2) > 0)       wrong(v2);     else {       cout <<  Y   << v1.size() <<   n ;       for (int i = 0; i < v1.size(); i++) {         if (i) cout <<    ;         cout << v1[i] + 1;       }       cout << endl;     }   }   