SPOJ Brasil

Aastha and Atul got so into each other during their date that they forgot to keep track of time. Now for students of our college in-time is a very serious issue. If a girl fails to reach her hostel before the stipulated time she will land up in a huge amount of trouble. Aastha doesn't want to land up in trouble so she asks you for help. She will provide you a map with many possible routes to her hostel The map will be a in the form of a set of roads. Your task is to tell her the minimum possible time within which she can reach there. Assume that the time taken to cover each road is 1 unit. Node 1 denotes the starting point and Node n denotes her hostel.

Input

First line contains T. T test cases follow.

First line of each test case contains two space-separated integers N, M.

Each of the next M lines contains two space-separated integers X and Y, denoting that there is a road between X and Y.

Output

Print the answer to each test case in a new line.

Constraints:

1 ≤ T ≤ 10

1 ≤ N ≤ 10^4

1 ≤ M ≤ 10^5

1 ≤ X, Y ≤ N

Example

Input:
2
3 2
1 2
2 3
4 4
1 2
2 3
3 4
4 2

Output:
2
2