func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     ios_base::sync_with_stdio(false), cout.tie(0), cin.tie(0);     int n;     cin >> n;     if (n <= 3) {       cout << 0 <<   n ;       return 0;     }     int Max = -1, k;     for (int i = 2; i < n; ++i) {       int tp = n / i * (i - 1);       if (n % i >= 1) tp += n % i - 1;       tp -= i - 1;       if (tp > Max) Max = tp, k = i;     }     set<int> Se;     vector<int> SS(n);     int a = n / k, ps = 0;     for (int i = 0; i < a; ++i) {       for (int j = 0; j < k; ++j) {         if (j == k - 1)           ps++;         else           Se.insert(ps++);       }     }     for (; ps < n - 1; ++ps) Se.insert(ps);     for (int i : Se) SS[i] = 1;     bool ok = 0;     while (!ok) {       vector<int> A;       for (int i = 0; i < k; ++i)         if (((int)(Se).size())) {           A.push_back(*Se.begin());           Se.erase(Se.begin());         }       if (((int)(Se).size()) == 0) ok = 1;       cout << ((int)(A).size()) <<    ;       for (int i : A) cout << i + 1 <<    ;       cout << endl;       cout.flush();       int l;       cin >> l;       --l;       for (int i = 0; i < k; ++i) {         if (SS[(i + l) % n]) Se.insert((i + l) % n);       }       if (ok) {         cout << 0 << endl;         cout.flush();       }     }     return 0;   }   