func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 1e6 + 2;   int ar[N], ar1[N];   signed main() {     ios::sync_with_stdio(0);     cin.tie(0);     int n, i, j, k, l, r;     long long sum;     cin >> n >> sum;     if (sum < 1ll * n * (n + 1) / 2) {       cout << -1;       return 0;     }     for (i = 1; i <= n; i++) {       ar[i] = i;       ar1[i] = i;     }     l = 1;     r = n;     sum -= 1ll * n * (n + 1) / 2;     while (sum && l < r) {       if (sum > r - l) {         sum -= (r - l);         swap(ar1[l], ar1[r]);         l++;         r--;       } else {         swap(ar1[r], ar1[r - sum]);         break;       }     }     sum = 0;     for (i = 1; i <= n; i++) {       sum += max(ar[i], ar1[i]);     }     cout << sum <<   n ;     for (i = 1; i <= n; i++) {       cout << ar[i] <<    ;     }     cout <<   n ;     for (i = 1; i <= n; i++) {       cout << ar1[i] <<    ;     }   }   