= 30 + 66 - (33 + 33) + 900 + 45 - 890*3 + 4 + 5 + 6 + 7 + 1 + 2
= 30 + 66 - 66 + 900 + 45 - 2670 + 4 + 5 + 6 + 7 + 1 + 2
= 30 + 0 + 900 + 45 - 2670 + 4 + 5 + 6 + 7 + 1 + 2
= 980 - 2670 + 4 + 5 + 6 + 7 + 1 + 2
= -1690 + 25
= -1665

Therefore, the final result is -1665.