import random


def choose_false_edges(non_edges, K):
    """
    Randomly choose a fixed number of non-existing edges
    :param non_edges: Edges that are not in the graph
    :param K: Fixed number of edges to choose
    :return: A list of K false edges
    """
    indexes = random.sample(range(1, len(non_edges)), K)
    false_edges = []
    for i in indexes:
        false_edges.append(non_edges[i])
    return false_edges