def get_edges(graph: dict) -> set:
    """
    Return a set of couples that represents all of the edges.
    @input: graph (graph stored in an adjacency list where each vertex is
            represented as an integer)
    @example:
    >>> graph = {0: [1, 3], 1: [0, 3], 2: [0, 3], 3: [0, 1, 2]}
    >>> get_edges(graph)
    {(0, 1), (3, 1), (0, 3), (2, 0), (3, 0), (2, 3), (1, 0), (3, 2), (1, 3)}
    """
    edges = set()
    for from_node, to_nodes in graph.items():
        for to_node in to_nodes:
            edges.add((from_node, to_node))
    return edges