A. Typical Interview Problemtime limit per test2 secondsmemory limit per test512 megabytesinputstandard inputoutputstandard outputThe 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:  if the current integer is divisible by 3, append F to the end of the FB-string;  if the current integer is divisible by 5, append B to the end of the FB-string. 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 \le l \le r) so that the string f_l f_{l+1} f_{l+2} \dots f_r is exactly s.For example:  FFB is a substring of the FB-string: if we pick l = 3 and r = 5, the string f_3 f_4 f_5 is exactly FFB;  BFFBFFBF is a substring of the FB-string: if we pick l = 2 and r = 9, the string f_2 f_3 f_4 \dots f_9 is exactly BFFBFFBF;  BBB is not a substring of the FB-string. InputThe first line contains one integer t (1 \le t \le 2046) — the number of test cases.Each test case consists of two lines. The first line contains one integer k (1 \le k \le 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.OutputFor 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).ExampleInput
33FFB8BFFBFFBF3BBBOutput
YES
YES
NO

33FFB8BFFBFFBF3BBB
YES YES NO 
['brute force', 'implementation', 'strings', '*800']