func_code_string: #include <bits/stdc++.h>   using namespace std;   const int MAX_N = 1e5 + 9;   int a[MAX_N];   void mergesort(int l, int r, int &k, int &remain) {     if (k > 0 && r - l > 1) {       k -= 2;       int m = (l + r) / 2;       mergesort(l, m, k, remain);       mergesort(m, r, k, remain);     } else {       int c = r - l;       for (int i = 0; i < c; i++) {         a[l + i] = remain - c + i + 1;       }       remain -= c;     }   }   int main() {     int n, k;     cin >> n >> k;     if (k % 2 == 0 || k > 2 * n - 1) {       return !printf( -1 );     }     int remain = n;     k -= 1;     mergesort(0, n, k, remain);     for (int i = 0; i < n; i++) {       printf( %d  , a[i]);     }   }   