B'Ashish has a string s of length n containing only characters 'a ', 'b ' and 'c '. He wants to find the length of the smallest substring, which satisfies the following conditions: Ashish is busy planning his next Codeforces round. Help him solve the problem. A string a is a substring of a string b if a can be obtained from b by deletion of several (possibly, zero or all) characters from the beginning and several (possibly, zero or all) characters from the end. The first line contains a single integer t (1 <= t <= 10^{5}) -- the number of test cases. The description of test cases follows. The first line of each test case contains a single integer n (2 <= n <= 10^{6}) -- the length of the string s . The second line of each test case contains a string s consisting only of characters 'a ', 'b ' and 'c '. It is guaranteed that the sum of n over all test cases does not exceed 10^{6} . For each test case, output the length of the smallest substring which satisfies the given conditions or print -1 if there is no such substring. Consider the first test case. In the substring "aa", 'a ' occurs twice, while 'b ' and 'c ' occur zero times. Since 'a ' occurs strictly more times than 'b ' and 'c ', the substring "aa" satisfies the condition and the answer is 2 . The substring "a" also satisfies this condition, however its length is not at least 2 . In the second test case, it can be shown that in none of the substrings of "cbabb" does 'a ' occur strictly more times than 'b ' and 'c ' each. In the third test case, "cacabccc", the length of the smallest substring that satisfies the conditions is 3 . '...