B'You are given a binary string s of length 2n where each element is mathtt{0} or mathtt{1} . You can do the following operation: Your task is to find a sequence of no more than 10 operations that changes all elements of s to mathtt{0} , or determine that it is impossible to do so. Note that you do not have to minimize the number of operations. Under the given constraints, it can be proven that if it is possible to change all elements of s to mathtt{0} , there exists a way that requires no more than 10 operations. ^ dagger A sequence of brackets is called balanced if one can turn it into a valid math expression by adding characters + and 1 . For example, sequences "(())()", "()", and "(()(()))" are balanced, while ")(", "(()", and "(()))(" are not. ^ ddagger If we perform a range toggle operation from l to r on a binary string s , then we toggle all values of s_i such that l <= q i <= q r . If s_i is toggled, we will set s_i := mathtt{0} if s_i = mathtt{1} or vice versa. For example, if s= mathtt{1000101} and we perform a range toggle operation from 3 to 5 , s will be changed to s= mathtt{1011001} . Each test contains multiple test cases. The first line contains the number of test cases t ( 1 <= t <= 1000 ). The description of the test cases follows. The first line of each test case contains a single integer n ( 1 <= n <= 2 cdot 10^5 ) -- where 2n is the length of string s . The second line of each test case contains a binary string s of length 2n ( s_i = mathtt{0} or s_i = mathtt{1} ). It is guaranteed that the sum of n over all test cases does not exceed 2 cdot 10^5 . For each test case, output -1 in a single line if it is impossible to change all elements of s to mathtt{0} . Otherwise, output a single integer '...