In a B-Tree, the block size is $512$ Bytes, search key is $4$ Bytes, block pointer size is $8$ Bytes and record pointer size is $8$ Bytes. Every node contains $n-1$ record pointers, $n-1$ search keys and n block pointers (where ‘$n$’ is the order of the B-tree).
The maximum number of search keys that can be accommodated in level $0$ of the above B-tree (where root is at level $0$) is _________.