Types: 
- N: int
- s: List[str]
- a: List[int]
- M: int
- t: List[str]
- b: List[int]
Ranges: 
- 1 ≤ N ≤ 50,000
- 0 ≤ a[i] ≤ 10^5
- 1 ≤ |s[i]| ≤ 20
- 1 ≤ M ≤ 20,000
- 0 ≤ b[j] ≤ 10^5
- 1 ≤ |t[j]| ≤ 20
Addtl Info: 
- s[i] and t[j] consist of English letters only
- No two incoming/outgoing events happen at the same time
- No two members have the same name initially, but members who left ACM once may join ACM again