func_code_string: #include <bits/stdc++.h>   const long long max9 = 10 + 1e9, max6 = 10 + 1e6, max12 = 10 + 1e12,                   max15 = 10 + 1e15;   const long long min6 = -1 * max6, min9 = -1 * max9, min12 = -1 * max12,                   min15 = -1 * max15;   const long long R = 7 + 1e9, NN = 10 + 1e5;   using namespace std;   int main() {     ios_base::sync_with_stdio(false);     cin.tie(NULL);     long long n;     long long k;     cin >> n >> k;     long long mn = n * (n + 1);     mn /= 2;     long long nn = n / 2 - 1, mx = 2 * (nn + 1) * n - nn * (nn + 1);     if (n % 2) mx += nn + 2;     if (k < mn) {       cout << -1;       return 0;     }     if (k >= mx) {       cout << mx << endl;       for (int i = (0); i < (n); ++i) cout << i + 1 <<    ;       cout << endl;       for (int i = (0); i < (n); ++i) cout << n - i <<    ;       return 0;     }     vector<int> a(n);     long long l = 0, last = n;     for (int i = (0); i < (n); ++i) a[i] = i + 1;     long long ben = k - mn;     for (int i = (0); i < (n / 2); ++i) {       if (ben == 0) break;       long long test = a[i] + ben;       if (test > last) {         a[i] = last;         a[last - 1] = i + 1;         ben -= last - i - 1;         last--;       } else {         a[i] = test;         a[test - 1] = i + 1;         break;       }     }     long long sum = 0;     for (int i = (0); i < (n); ++i) sum += max(i + 1, a[i]);     cout << sum << endl;     for (int i = (0); i < (n); ++i) cout << i + 1 <<    ;     cout << endl;     for (int i = (0); i < (n); ++i) cout << a[i] <<    ;     return 0;   }   