func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n;     long long k;     cin >> n >> k;     k -= (long long)n * (n + 1) / 2;     if (k < 0) {       cout << -1 << endl;       return 0;     }     long long sum = (long long)n * (n + 1) / 2;     vector<int> ans;     for (int i = n - 1; i >= 0; i--) {       int add = max(0, n - 1 - (n - 1 - i) * 2);       if (k > add) {         ans.push_back(i);         ans[n - 1 - i] = i;         k -= add;         sum += add;       } else {         for (int j = 0; j < i; j++) {           ans.push_back(j);         }         ans.insert(ans.begin() + (n - 1 - i) + (add - k), i);         sum += k;         break;       }     }     cout << sum << endl;     for (int i = 0; i < n; i++) {       cout << i + 1;       if (i < n - 1) {         cout <<    ;       }     }     cout << endl;     for (int i = 0; i < n; i++) {       cout << ans[i] + 1;       if (i < n - 1) {         cout <<    ;       }     }     cout << endl;   }   