def METHOD_NAME(nodes, count):
    next_nodes = set()
    for n in nodes:
        if n in node_scores:
            continue
        node_scores[n] = count
        if n == src_node:
            return
        if n in reverse_node_node:
            for nn in reverse_node_node[n]:
                if nn not in node_scores and nn not in blocked_nodes:
                    next_nodes.add(nn)
    METHOD_NAME(next_nodes, count + 1)