Playlist Management

This problem simulates a music streaming service's playlist. The playlist supports four operations:

• add x: Append song ID x to the end of the playlist.
• remove x: Remove the first occurrence of song ID x from the playlist (if it exists).
• find x: Return the 1-indexed position of the first occurrence of song ID x in the playlist. If the song is not found, return -1.
• query x: Return the song ID at the 1-indexed position x in the playlist. If the position is out of range, return -1.

All positions are 1-indexed. Your task is to process all operations sequentially and print the results of the find and query operations one per line.

Note: If a song to be removed is not present, do nothing.

The mathematical formulation for the position is given by: \[ \text{position} = \begin{cases} \text{index of } x + 1, & \text{if } x \text{ exists in the list}\\ -1, & \text{otherwise} \end{cases} \]

inputFormat

The input is read from stdin and consists of:

1. An integer q denoting the number of queries.
2. q lines each containing a query of the form:

• add x
• remove x
• find x
• query x

Here, x is an integer.

outputFormat

For each find or query operation, output the answer on a separate line to stdout.

## sample

5
add 101
add 203
find 101
query 2
remove 101

1
203

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