Sarah's Stamp Collection

Sarah owns a collection of stamps. Initially, she has n stamps with given values. Then she performs q queries on her collection. Each query is in one of the following two forms:

• 1 v: Add a stamp with value v to the collection. If the stamp already exists, nothing happens.
• 2 v: Check if a stamp with value v is present in the collection. Print YES if it exists, or NO otherwise.

The task is to process all queries. For each query of type 2, output the corresponding answer.

Note: The query operations modify the collection in real time. There is no need to worry about duplicates when adding; simply maintain the collection.

The mathematical model can be interpreted as managing a set \(S\) initially containing \(n\) elements. For each query:

• For type 1: \(S = S \cup \{v\}\).
• For type 2: Check if \(v \in S\) and report accordingly.

inputFormat

The input is given via standard input (stdin) and has the following format:

1. The first line contains two integers \(n\) and \(q\), representing the number of initial stamps and the number of queries, respectively.
2. The second line contains \(n\) space-separated integers, the values of the initial stamps. If \(n = 0\), this line will be empty.
3. The next \(q\) lines each contain two integers. The first integer is the query type (either 1 or 2) and the second integer is the value \(v\).

outputFormat

For each query of type 2, output a single line containing YES if a stamp with the given value exists in the collection, or NO otherwise. Output is via standard output (stdout).

## sample

5 7
30 10 50 20 40
2 10
2 35
1 35
2 35
1 75
2 75
2 30

YES
NO
YES
YES
YES

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