Description: On Penacony, The Land of the Dreams, there exists $$$n$$$ houses and $$$n$$$ roads. There exists a road between house $$$i$$$ and $$$i+1$$$ for all $$$1 \leq i \leq n-1$$$ and a road between house $$$n$$$ and house $$$1$$$. All roads are bidirectional. However, due to the crisis on Penacony, the overseeing family has gone into debt and may not be able to maintain all roads. There are $$$m$$$ pairs of friendships between the residents of Penacony. If the resident living in house $$$a$$$ is friends with the resident living in house $$$b$$$, there must be a path between houses $$$a$$$ and $$$b$$$ through maintained roads. What is the minimum number of roads that must be maintained? Input Format: The first line contains $$$t$$$ ($$$1 \leq t \leq 10^4$$$) – the number of test cases. The first line of each test case contains two integers $$$n$$$ and $$$m$$$ ($$$3 \leq n \leq 2 \cdot 10^5, 1 \leq m \leq 2 \cdot 10^5$$$) – the number of houses and the number of friendships. The next $$$m$$$ lines contain two integers $$$a$$$ and $$$b$$$ ($$$1 \leq a < b \leq n$$$) – the resident in house $$$a$$$ is friends with the resident in house $$$b$$$. It is guaranteed all ($$$a, b$$$) are distinct. It is guaranteed the sum of $$$n$$$ and $$$m$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$. Output Format: For each test case, output an integer, the minimum number of roads that must be maintained. Note: For the first test case, the following roads must be maintained: - $$$8 \leftarrow \rightarrow 1$$$ - $$$7 \leftarrow \rightarrow 8$$$ - $$$1 \leftarrow \rightarrow 2$$$ - $$$4 \leftarrow \rightarrow 5$$$