<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def symmetric_rcm(A):
 """Symmetric Reverse Cutthill-McKee. Parameters A : sparse matrix Sparse matrix Returns ------- B : sparse matrix Permuted matrix with reordering Notes ----- Get a pseudo-peripheral node, then call BFS Examples -------- See Also -------- pseudo_peripheral_node """

    n = A.shape[0]

    root, order, level = pseudo_peripheral_node(A)

    Perm = sparse.identity(n, format='csr')
    p = level.argsort()
    Perm = Perm[p, :]

    return Perm * A * Perm.T