B"The FB-string is formed as follows. Initially, it is empty. We go through all positive integers, starting from 1 , in ascending order, and do the following for each integer: Note that if an integer is divisible by both 3 and 5 , we append F, and then B, not in the opposite order. The first 10 characters of the FB-string are FBFFBFFBFB: the first F comes from the integer 3 , the next character (B) comes from 5 , the next F comes from the integer 6 , and so on. It's easy to see that this string is infinitely long. Let f_i be the i -th character of FB-string; so, f_1 is F, f_2 is B, f_3 is F, f_4 is F, and so on. You are given a string s , consisting of characters F and/or B. You have to determine whether it is a substring (contiguous subsequence) of the FB-string. In other words, determine if it is possible to choose two integers l and r ( 1 <= l <= r ) so that the string f_l f_{l+1} f_{l+2} ... f_r is exactly s . For example: The first line contains one integer t ( 1 <= t <= 2046 ) -- the number of test cases. Each test case consists of two lines. The first line contains one integer k ( 1 <= k <= 10 ) -- the number of characters in s . The second line contains s , which is a string of exactly k characters. Each character of s is either F or B. For each test case, print YES if s is a substring of the FB-string, or NO otherwise. You may print each letter in any case (YES, yes, Yes will all be recognized as positive answer, NO, no and nO will all be recognized as negative answer). "...