Duplicate Stamps Finder

You are given several batches of stamps. Each batch is represented by an integer m followed by m stamp IDs. Some stamps may appear only once while others may be duplicated.

Your task is to identify all the duplicate stamp IDs in each batch. If a batch does not have any duplicates, print No duplicates. Otherwise, print the duplicate stamp IDs separated by a single space. The order of stamp IDs should follow the order of their first occurrence in the batch.

Formally, for each batch we want to find all x such that:

\( \text{count}(x) > 1 \)

inputFormat

The input is given via stdin and consists of multiple batches.

• The first line contains an integer T denoting the number of batches.
• For each batch:
• The first line contains an integer m, the number of stamps in that batch.
• The next line contains m space-separated integers representing the stamp IDs.

outputFormat

For each batch, output a single line:

• If there are duplicate stamp IDs, print them separated by a single space in the order of their first occurrence.
• If there are no duplicates, print No duplicates.

The output should be written to stdout.

## sample

1
5
1 2 3 4 5

No duplicates

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