func_code_string: #include <bits/stdc++.h>   using namespace std;   int f(int k) {     int p = 1;     while ((p * (p + 1)) / 2 < k) p++;     if (k == (p * (p + 1)) / 2) return 0;     p--;     return (p * (p + 1)) / 2;   }   int main() {     int n;     int p = 1;     cin >> n;     int k = int((sqrt((8 * n) + 1)) + 1) / 2;     cout << k << endl;     vector<int> a[k + 1];     for (int j = 2; j <= k; j++)       for (int i = 1; i < j; i++) {         a[i].push_back(p);         a[j].push_back(p);         p++;       }     if (f(n))       for (int i = f(n) + 1; i <= n; i++) {         a[1].push_back(i);         a[2].push_back(i);       }     for (int i = 1; i <= k; i++) {       for (int j = 0; j < a[i].size(); j++) cout << a[i][j] <<    ;       cout << endl;     }     return 0;   }   