def get_index_of_most_important_sentences(weighted_sums, num_vectors):
    """ Finds and returns the index of the two sentences with the highest weighted sum """
    largest_sum_index, second_largest_sum_index = 0, 0
    largest_sum, second_largest_sum = 0, 0
    for i in range(num_vectors):
        current_sum = weighted_sums[i]
        if current_sum > largest_sum:
            largest_sum = current_sum
            largest_sum_index = i
        elif current_sum > second_largest_sum:
            second_largest_sum = current_sum
            second_largest_sum_index = i
    
    return largest_sum_index, second_largest_sum_index