You are given two arrays (a) and (b) of length (n), consisting only of (0) and (1). You may perform the following operation on (a) any number of times: Choose (k) indices (1 \le i_1 \lt i_2 \lt \ldots \lt i_k \le n), where (1 \le k \le n) and (\sum\limits_{j = 1}^k a_{i_j}) is odd . In other words, choose a non-empty subsequence(^{\text{∗}}) of (a) with an odd sum. For each (1 \le j \le k), set (a_{i_j} = 1 - a_{i_j}). In other words, invert all elements of the chosen subsequence. Find the minimum number of operations needed to transform (a) into (b), or determine that it is impossible. (^{\text{∗}})A sequence (c) is a subsequence of a sequence (d) if (c) can be obtained from (d) by the deletion of several (possibly, zero or all) elements from arbitrary positions. Each test contains multiple test cases. The first line contains the number of test cases (t) ((1 \le t \le 10^4)). The description of the test cases follows. The first line of each test case contains a single integer (n) ((1 \le n \le 2 \cdot 10^5)) — the length of the arrays (a) and (b). The second line of each test case contains (n) integers (a_1, a_2, \ldots, a_n) ((a_i \in \{0, 1\})) — array (a). The third line of each test case contains (n) integers (b_1, b_2, \ldots, b_n) ((b_i \in \{0, 1\})) — array (b). It is guaranteed that the sum of (n) over all test cases does not exceed (2 \cdot 10^5). For each test case, output a single integer — the minimum number of operations needed to transform (a) into (b), or (-1) if it is impossible. In the first example, (a = b), so no operations are needed. Therefore, the answer is (0). In the second example, we can perform an operation with the subsequence (a_1, a_2). The sum of its elements is (1 + 0 = 1), which is odd. This operation transforms (a) as follows: $$$[\color{red}