题目描述
Given is an undirected graph G consisting of N vertices numbered 1 through N and M edges numbered 1 through M.
Edge i connects Vertex a_i and Vertex b_i bidirectionally.
G is said to be a good graph when both of the conditions below are satisfied. It is guaranteed that G is initially a good graph.
- Vertex 1 and Vertex N are not connected.
- There are no self-loops and no multi-edges.
Taro the first and Jiro the second will play a game against each other.
They will alternately take turns, with Taro the first going first.
In each player's turn, the player can do the following operation:
- Operation: Choose vertices u and v, then add to G an edge connecting u and v bidirectionally.
The player whose addition of an edge results in G being no longer a good graph loses. Determine the winner of the game when the two players play optimally.
You are given T test cases. Solve each of them.
-----Constraints-----
- All values in input are integers.
- $1 \leq T \leq 10^5$
- $2 \leq N \leq 10^{5}$
- $0 \leq M \leq \min(N(N-1)/2,10^{5})$
- $1 \leq a_i,b_i \leq N$
- The given graph is a good graph.
- In one input file, the sum of N and that of M do not exceed $2 \times 10^5$.
-----Input-----
Input is given from Standard Input in the following format:
T
$\mathrm{case}_1$
$\vdots$
$\mathrm{case}_T$
Each case is in the following format:
N M
a_1 b_1
$\vdots$
a_M b_M
-----Output-----
Print T lines. The i-th line should contain First if Taro the first wins in the i-th test case, and Second if Jiro the second wins in the test case.
-----Sample Input-----
3
3 0
6 2
1 2
2 3
15 10
12 14
8 3
10 1
14 6
12 6
1 9
13 1
2 5
3 9
7 2
-----Sample Output-----
First
Second
First
- In test case 1, Taro the first wins. Below is one sequence of moves that results in Taro's win:
- In Taro the first's turn, he adds an edge connecting Vertex 1 and 2, after which the graph is still good.
- Then, whichever two vertices Jiro the second would choose to connect with an edge, the graph would no longer be good.
- Thus, Taro wins.
输入格式
见题面
输出格式
见题面