B'You are given a string s of length n consisting of lowercase Latin characters. Find the length of the shortest string k such that several (possibly one) copies of k can be concatenated together to form a string with the same length as s and, at most, one different character. More formally, find the length of the shortest string k such that c = underbrace{k + cdots + k}_{x rm text{times}} for some positive integer x , strings s and c has the same length and c_i neq s_i for at most one i (i.e. there exist 0 or 1 such positions). The first line contains a single integer t ( 1 <= q t <= q 10^3 ) -- the number of test cases. The first line of each test case contains a single integer n ( 1 <= q n <= q 2 cdot10^5 ) -- the length of string s . The second line of each test case contains the string s , consisting of lowercase Latin characters. The sum of n over all test cases does not exceed 2 cdot10^5 . For each test case, print the length of the shortest string k satisfying the constraints in the statement. In the first test case, you can select k = texttt{a} and k+k+k+k = texttt{aaaa} , which only differs from s in the second position. In the second test case, you cannot select k of length one or two. We can have k = texttt{abba} , which is equal to s . '...