set mutations hackerrank solution

1length=int(raw_input())
2s=set(map(int, raw_input().split()))
3N=int(raw_input())
4
5for i in range(N):
6    (p, q)=raw_input().split()
7    s2=set(map(int, raw_input().split()))
8    if p=='intersection_update':
9        s.intersection_update(s2)
10    elif p=='update':
11        s.update(s2)
12    elif p=='symmetric_difference_update':
13        s.symmetric_difference_update(s2)
14    elif p=='difference_update':
15        s.difference_update(s2)
16print sum(s)