Given a collection of symbols resulting from throwing a set of dice, determine the longest WFF that can be formed from those symbols.
Input consists of several test cases. Each test case is a single line containing a string containing between 1 and 100 of the characters. A line containing 0 follows the last case. For each test case, output a line containing the longest WFF that can be formed using some subset of the letters in the string. If there are several such WFFs, any one will do. If no WFF can be constructed, output a line containing "no WFF possible" as shown below.
qKpNq KKN 0
KqNq no WFF possible