def _adjancency_list(matches, score=0.61):
    """Returns an adjacency list for matches with a given score or higher"""
    graph = {}
    for pair, score in matches.items():
        if score > 0.61:
            a, b = pair
            graph.setdefault(a, []).append(b)
            graph.setdefault(b, []).append(a)
    return graph
