13:I[87,["736","static/chunks/89fc4f0e-9e200ae6a0166583.js","401","static/chunks/363642f4-32903b9154b7835a.js","153","static/chunks/153-58eddeb032cc4608.js","131","static/chunks/131-05ce00cfd760e12b.js","87","static/chunks/87-b76b60eef573119a.js","286","static/chunks/app/problem/%5Bid%5D/page-45cf3875257fc32e.js"],"Header"] 14:I[1742,["736","static/chunks/89fc4f0e-9e200ae6a0166583.js","401","static/chunks/363642f4-32903b9154b7835a.js","153","static/chunks/153-58eddeb032cc4608.js","131","static/chunks/131-05ce00cfd760e12b.js","87","static/chunks/87-b76b60eef573119a.js","286","static/chunks/app/problem/%5Bid%5D/page-45cf3875257fc32e.js"],"ProblemView"] 15:T7a3,

You are given a sequence $$$a_1, a_2, \ldots, a_n$$$. Each element of $$$a$$$ is $$$1$$$ or $$$2$$$.

Find out if an integer $$$k$$$ exists so that the following conditions are met.

$$$1 \leq k \leq n-1$$$, and
$$$a_1 \cdot a_2 \cdot \ldots \cdot a_k = a_{k+1} \cdot a_{k+2} \cdot \ldots \cdot a_n$$$.

If there exist multiple $$$k$$$ that satisfy the given condition, print the smallest.

Input

Each test contains multiple test cases. The first line contains the number of test cases $$$t$$$ ($$$1 \le t \le 100$$$). Description of the test cases follows.

The first line of each test case contains one integer $$$n$$$ ($$$2 \leq n \leq 1000$$$).

The second line of each test case contains $$$n$$$ integers $$$a_1, a_2, \ldots, a_n$$$ ($$$1 \leq a_i \leq 2$$$).

Output

For each test case, if there is no such $$$k$$$, print $$$-1$$$.

Otherwise, print the smallest possible

One and Two

Examples