A. One and Twotime limit per test1 secondmemory limit per test256 megabytesinputstandard inputoutputstandard outputYou 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.InputEach 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).OutputFor each test case, if there is no such k, print -1.Otherwise, print the smallest possible k.ExampleInput
362 2 1 2 1 231 2 141 1 1 1Output
2
-1
1
NoteFor the first test case, k=2 satisfies the condition since a_1 \cdot a_2 = a_3 \cdot a_4 \cdot a_5 \cdot a_6 = 4. k=3 also satisfies the given condition, but the smallest should be printed.For the second test case, there is no k that satisfies a_1 \cdot a_2 \cdot \ldots \cdot a_k = a_{k+1} \cdot a_{k+2} \cdot \ldots \cdot a_nFor the third test case, k=1, 2, and 3 satisfy the given condition, so the answer is 1.
362 2 1 2 1 231 2 141 1 1 1
2 -1 1 
['brute force', 'implementation', 'math', '*800']