Second Smallest Unique Integer

You are given several test cases. In each test case, a sequence of integers is provided on a single line separated by spaces. The task is to determine the second smallest unique integer in the sequence. If the sequence contains fewer than two unique integers, output -1.

Problem Details:

• For each test case, remove duplicate integers and sort the remaining unique values in increasing order.
• If there are at least two unique numbers, return the second smallest number; otherwise, return -1.

The input begins with an integer T indicating the number of test cases, followed by T lines each representing a test case. The expected output is the result for each test case printed on a new line.

For mathematical notation in LaTeX, let \( S \) be the set of unique integers extracted from the list. If \( |S| \ge 2 \), then the answer is the second smallest element in \( S \); otherwise, the answer is \( -1 \).

inputFormat

The input is read from standard input (stdin) and has the following format:

T
line_1
line_2
...
line_T

Where:

• T is a positive integer representing the number of test cases.
• Each line_i contains a sequence of space-separated integers representing a single test case.

outputFormat

For each test case, output the second smallest unique integer on a separate line. If there are fewer than two unique integers in the test case, output -1.

The output is written to standard output (stdout) with each answer on a new line.

## sample

4
1 3 4 2 1 2
5 5 5 5
2 1
10

2
-1
2
-1

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