Solve the programming task below in a Python markdown code block.
Read problem statements in [Russian]

Chef has a sequence $A_{1}, A_{2}, \ldots, A_{N}$. In one operation, Chef can choose one index $i$ ($1 ≤ i ≤ N$) and change $A_{i}$ to $A_{i}^{p}$, where $p = \max(0, {\lceil \frac{A_{i}}{2} \rceil} - 1)$.

Help Chef find the smallest number of operations needed to make the sum of the sequence even or determine that it is impossible.

------  Input ------
The first line of the input contains a single integer $T$ denoting the number of test cases. The description of $T$ test cases follows.
The first line of each test case contains a single integer $N$.
The second line contains $N$ space-separated integers $A_{1}, A_{2}, \ldots, A_{N}$.

------  Output ------
For each test case, print a single line containing one integer — the minimum number of operations needed to make the sum of the sequence even, or $-1$ if it is impossible.

------  Constraints ------
$1 ≤ T ≤ 10$
$1 ≤ N ≤ 10^{5}$
$1 ≤ A_{i} ≤ 10^{9}$ for each valid $i$

------  Subtasks ------
Subtask #1 (30 points):
$N ≤ 100$
$1 ≤ A_{i} ≤ 10$ for each valid $i$

Subtask #2 (70 points): original constraints

----- Sample Input 1 ------ 
4

4

7 3 5 1

5

4 2 7 8 10

2

9 9

3

1 1 1
----- Sample Output 1 ------ 
0

1

0

-1
----- explanation 1 ------ 
Example case 1: The sum of the sequence is $16$, which is already even.

Example case 2: We can change $A_{2}$ to $1$, so that the sequence becomes $[4, 1, 7, 8, 10]$. The sum of this sequence is $30$, which is even.

Example case 3: The sum of the sequence is $18$, which is already even.

Example case 4: It is impossible to make the sum of the sequence even.