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Problem N
Guest List

Languages en is
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A new hotel has implemented strict entry rules, allowing access only to those on a special guest list. Due to high demand and technical issues with maintaining the list on paper, a command-line program is needed to register, remove, and check names on the list.

Input

  • The first line contains the positive integer $N$, representing the number of commands that follow.

  • The next $N$ lines contain commands of the following types:

    • + name – Adds a name to the guest list.

    • - name – Removes a name from the guest list.

    • ? name – Checks whether a name is on the guest list.

Names only include the English lowercase letters a to z and names are at most $8$ characters in length. A name that’s already on the list will never be added again, and no name will be removed that’s not on the list.

Output

For each ? name command, the program should print Jebb if the name is on the list, otherwise Neibb.

Scoring

Group

Score

Constraints

1

20

Only ? name commands and $N \leq 20$.

2

50

$N \leq 1\, 000$.

3

30

$N \leq 200\, 000$.

Sample Input 1 Sample Output 1
5
+ alex
? alex
? eva
+ eva
? eva
Jebb
Neibb
Jebb
Sample Input 2 Sample Output 2
8
+ alex
? alex
- alex
? alex
+ eva
? eva
- eva
? eva
Jebb
Neibb
Jebb
Neibb

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