func_code_string: #include <bits/stdc++.h>   int arr[100005];   int k;   void unsort(int left, int right) {     if (k <= 0 || left >= right - 1) return;     int mid = (left + right) / 2;     std::swap(arr[mid - 1], arr[mid]);     --k;     unsort(left, mid);     unsort(mid, right);   }   int main() {     int n;     scanf( %d%d , &n, &k);     if (k % 2 == 0 || k > 2 * n) {       printf( -1 n );       return 0;     }     for (int i = 0; i < n; ++i) {       arr[i] = i + 1;     }     k /= 2;     unsort(0, n);     for (int i = 0; i < n; ++i) {       printf( %d  , arr[i]);     }     printf(  n );     return 0;   }   