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A13617. Sequential Nim

编程题 普及/提高-

题目描述

There are $n$ piles of stones, where the $i$ -th pile has $a_i$ stones. Two people play a game, where they take alternating turns removing stones.

In a move, a player may remove a positive number of stones from the first non-empty pile (the pile with the minimal index, that has at least one stone). The first player who cannot make a move (because all piles are empty) loses the game. If both players play optimally, determine the winner of the game.

输入格式

The first line contains a single integer $t$ ( $1\le t\le 1000$ ) — the number of test cases. Next $2t$ lines contain descriptions of test cases.

The first line of each test case contains a single integer $n$ ( $1\le n\le 10^5$ ) — the number of piles.

The second line of each test case contains $n$ integers $a_1,\ldots,a_n$ ( $1\le a_i\le 10^9$ ) — $a_i$ is equal to the number of stones in the $i$ -th pile.

It is guaranteed that the sum of $n$ for all test cases does not exceed $10^5$ .

输出格式

For each test case, if the player who makes the first move will win, output "First". Otherwise, output "Second".

输入输出样例

输入 #1
7
3
2 5 4
8
1 1 1 1 1 1 1 1
6
1 2 3 4 5 6
6
1 1 2 1 2 2
1
1000000000
5
1 2 2 1 1
3
1 1 1
输出 #1
First
Second
Second
First
First
Second
First

说明/提示

In the first test case, the first player will win the game. His winning strategy is:

1. The first player should take the stones from the first pile. He will take $1$ stone. The numbers of stones in piles will be $[1, 5, 4]$ .
2. The second player should take the stones from the first pile. He will take $1$ stone because he can't take any other number of stones. The numbers of stones in piles will be $[0, 5, 4]$ .
3. The first player should take the stones from the second pile because the first pile is empty. He will take $4$ stones. The numbers of stones in piles will be $[0, 1, 4]$ .
4. The second player should take the stones from the second pile because the first pile is empty. He will take $1$ stone because he can't take any other number of stones. The numbers of stones in piles will be $[0, 0, 4]$ .
5. The first player should take the stones from the third pile because the first and second piles are empty. He will take $4$ stones. The numbers of stones in piles will be $[0, 0, 0]$ .
6. The second player will lose the game because all piles will be empty.
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