Efficient Number Set Operations

You are provided with a series of operations to perform on a set of integers. The operations are defined as follows:

• Add (Query Type 1): Add an integer \(x\) to the set. It is guaranteed that \(x\) is not already present in the set.
• Remove (Query Type 2): Remove an integer \(x\) from the set. It is guaranteed that \(x\) is present in the set.
• Check (Query Type 3): Check if an integer \(x\) is present in the set. Print YES if it is present and NO otherwise.

You will be given \(n\) queries. Process these queries sequentially, and for each query of type 3, output the result as described above.

inputFormat

The input begins with an integer \(n\) on the first line, representing the number of queries. Each of the next \(n\) lines contains two space-separated integers \(t\) and \(x\), where \(t\) indicates the type of operation (1, 2, or 3), and \(x\) is the integer to be processed.

outputFormat

For every query of type 3, output the result on a new line. The output should be YES if \(x\) is present in the set at the time of the query, and NO otherwise.

## sample

6
1 5
1 10
3 5
2 5
3 5
3 10

YES
NO
YES

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