B'A row of n cells is given, all initially white. Using a stamp, you can stamp any two neighboring cells such that one becomes red and the other becomes blue. A stamp can be rotated, i.e. it can be used in both ways: as color{blue}{ texttt{B}} color{red}{ texttt{R}} and as color{red}{ texttt{R}} color{blue}{ texttt{B}} . During use, the stamp must completely fit on the given n cells (it cannot be partially outside the cells). The stamp can be applied multiple times to the same cell. Each usage of the stamp recolors both cells that are under the stamp. For example, one possible sequence of stamps to make the picture color{blue}{ texttt{B}} color{red}{ texttt{R}} color{blue}{ texttt{B}} color{blue}{ texttt{B}} texttt{W} could be texttt{WWWWW} to texttt{WW} color{brown}{ underline{ color{red}{ texttt{R}} color{blue}{ texttt{B}}}} texttt{W} to color{brown}{ underline{ color{blue}{ texttt{B}} color{red}{ texttt{R}}}} color{red}{ texttt{R}} color{blue}{ texttt{B}} texttt{W} to color{blue}{ texttt{B}} color{brown}{ underline{ color{red}{ texttt{R}} color{blue}{ texttt{B}}}} color{blue}{ texttt{B}} texttt{W} . Here texttt{W} , color{red}{ texttt{R}} , and color{blue}{ texttt{B}} represent a white, red, or blue cell, respectively, and the cells that the stamp is used on are marked with an underline. Given a final picture, is it possible to make it using the stamp zero or more times? The first line contains an integer t ( 1 <= q t <= q 10^4 ) -- the number of test cases. The first line of each test case contains an integer n ( 1 <= q n <= q 10^5 ) -- the length of the picture. The second line of each test case contains a string s -- the picture you need to make. It is guaranteed that the length of s is n and that s only consists of the characters texttt{W} , texttt{R} , and texttt{B} , representing a white, red, or blue cell, respectively.'...