Find the Missing Book ID

You are given a total number of books n that are sequentially numbered from 1 to n. However, one of the book IDs is missing from the records. You are provided with a list of n - 1 logged book IDs. Your task is to find the missing book ID.

You can use the formula for the sum of the first n natural numbers, which is given by:

\( \frac{n(n+1)}{2} \)

Subtract the sum of the logged book IDs from this total sum to determine the missing ID.

inputFormat

The input is read from stdin and follows the format below:

• The first line contains an integer T, the number of test cases.
• For each test case:
• The first line contains the integer n, representing the total number of books.
• The second line contains n - 1 space-separated integers which are the logged book IDs. If there are no logged IDs, the line will be empty.

outputFormat

For each test case, output a single integer on a new line which represents the missing book ID. The output is printed to stdout.

## sample

2
5
1 2 3 5
4
3 1 4

4
2

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