import networkx as nx

def parades(digraf, origen, desti):
    if origen in digraf and desti in digraf and nx.has_path(digraf, origen, desti):
        r = (
            nx.shortest_path_length(digraf, origen, desti)-1,
            nx.shortest_path(digraf, origen, desti)[1:][:-1]
        )
    else:
        r = (-1, [])
    return r