Identify like terms in the following:
10pq, 7p, 8q, −p2q2, −7qp, −100q, −23, 12q2p2, −5p2, 41, 2,405p, 78qp, 13p2q, qp2, 701p2
Add: 2p2q2−3pq+4 and 5+7pq−3p2q2