func_code_string: #include <bits/stdc++.h>   using namespace std;   int n;   vector<int> ans[1000];   int main() {     cin >> n;     int k = 2;     while ((k * (k + 1)) / 2 <= n) k++;     int cnt = 1;     for (int i = 1; i <= k; i++)       for (int j = 1; j < i; j++) {         ans[i].push_back(cnt);         ans[j].push_back(cnt);         cnt++;       }     cout << k << endl;     for (int i = 1; i <= k; i++) {       for (int j = 0; j < ans[i].size(); j++) cout << ans[i][j] <<    ;       cout << endl;     }     return 0;   }   