func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 5e5 + 7;   const int mod = 998244353;   int ans[1007][1007];   int num[1007];   int n, k;   void print(int l, int r) {     cout <<  ?   << r - l + 1 <<    ;     for (int i = l; i <= r; i++) cout << i <<    ;     cout << endl;     fflush(stdout);   }   int ggg(int x) {     for (int i = 1; i <= k; i++)       for (int j = 1; j <= num[i]; j++) {         if (ans[i][j] == x) {           return i;         }       }   }   int main() {     ios::sync_with_stdio(false);     int zs;     cin >> zs;     while (zs--) {       cin >> n >> k;       for (int i = 1; i <= k; i++) {         cin >> num[i];         for (int j = 1; j <= num[i]; j++) cin >> ans[i][j];       }       int ma;       print(1, n);       cin >> ma;       int l = 1, r = n;       while (l < r) {         int mid = (l + r) / 2;         print(l, mid);         int x;         cin >> x;         if (x == ma)           r = mid;         else           l = mid + 1;       }       int t = ggg(l);       int vis[1007] = {0};       for (int i = 1; i <= num[t]; i++) vis[ans[t][i]] = 1;       cout <<  ?   << n - num[t] <<    ;       for (int i = 1; i <= n; i++)         if (!vis[i]) cout << i <<    ;       cout << endl;       fflush(stdout);       int se;       cin >> se;       cout <<  !  <<    ;       for (int i = 1; i <= k; i++)         if (i == t)           cout << se <<    ;         else           cout << ma <<    ;       cout << endl;       string s;       cin >> s;     }   }   