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S-Nim

Time Limit : 5000/1000ms (Java/Other)   Memory Limit : 65536/32768K (Java/Other)
Total Submission(s) : 0   Accepted Submission(s) : 0
Problem Description
Arthur and his sister Caroll have been playing a game called Nim for some time now. Nim is played as follows:<br><br><br>&nbsp;&nbsp;The starting position has a number of heaps, all containing some, not necessarily equal, number of beads.<br><br>&nbsp;&nbsp;The players take turns chosing a heap and removing a positive number of beads from it.<br><br>&nbsp;&nbsp;The first player not able to make a move, loses.<br><br><br>Arthur and Caroll really enjoyed playing this simple game until they recently learned an easy way to always be able to find the best move:<br><br><br>&nbsp;&nbsp;Xor the number of beads in the heaps in the current position (i.e. if we have 2, 4 and 7 the xor-sum will be 1 as 2 xor 4 xor 7 = 1).<br><br>&nbsp;&nbsp;If the xor-sum is 0, too bad, you will lose.<br><br>&nbsp;&nbsp;Otherwise, move such that the xor-sum becomes 0. This is always possible.<br><br><br>It is quite easy to convince oneself that this works. Consider these facts:<br><br>&nbsp;&nbsp;The player that takes the last bead wins.<br><br>&nbsp;&nbsp;After the winning player's last move the xor-sum will be 0.<br><br>&nbsp;&nbsp;The xor-sum will change after every move.<br><br><br>Which means that if you make sure that the xor-sum always is 0 when you have made your move, your opponent will never be able to win, and, thus, you will win. <br><br>Understandibly it is no fun to play a game when both players know how to play perfectly (ignorance is bliss). Fourtunately, Arthur and Caroll soon came up with a similar game, S-Nim, that seemed to solve this problem. Each player is now only allowed to remove a number of beads in some predefined set S, e.g. if we have S =(2, 5) each player is only allowed to remove 2 or 5 beads. Now it is not always possible to make the xor-sum 0 and, thus, the strategy above is useless. Or is it? <br><br>your job is to write a program that determines if a position of S-Nim is a losing or a winning position. A position is a winning position if there is at least one move to a losing position. A position is a losing position if there are no moves to a losing position. This means, as expected, that a position with no legal moves is a losing position.
 

Input
Input consists of a number of test cases. For each test case: The first line contains a number k (0 < k ¡Ü 100 describing the size of S, followed by k numbers si (0 < si ¡Ü 10000) describing S. The second line contains a number m (0 < m ¡Ü 100) describing the number of positions to evaluate. The next m lines each contain a number l (0 < l ¡Ü 100) describing the number of heaps and l numbers hi (0 ¡Ü hi ¡Ü 10000) describing the number of beads in the heaps. The last test case is followed by a 0 on a line of its own.
 

Output
For each position: If the described position is a winning position print a 'W'.If the described position is a losing position print an 'L'. Print a newline after each test case.<br>
 

Sample Input
2 2 5<br>3<br>2 5 12<br>3 2 4 7<br>4 2 3 7 12<br>5 1 2 3 4 5<br>3<br>2 5 12<br>3 2 4 7<br>4 2 3 7 12<br>0<br>
 

Sample Output
LWW<br>WWL<br>
 

Source
Norgesmesterskapet 2004
 

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