def remove_items_in_a_from_b(left, right):
    left_lines = open(left, 'r').readlines()
    right_lines = open(right, 'r').readlines()

    return [line for line in right_lines if line not in left_lines]

if __name__ == '__main__':
    import os
    import sys

    left = os.path.expanduser(sys.argv[1])
    right = os.path.expanduser(sys.argv[2])
    print(f' LEFT: {left}')
    print(f'RIGHT: {right}')
    unique_in_b = remove_items_in_a_from_b(left, right)
    print("___________")
    print(''.join(unique_in_b))