Exclusive-OR

Time Limit: 2000/1000 MS (Java/Others)

Memory Limit: 32768/32768 K (Java/Others)

Description

You are not given n non-negative integers X0, X1, ..., Xn-1 less than 220 , but they do exist, and their values never change.

I'll gradually provide you some facts about them, and ask you some questions.

There are two kinds of facts, plus one kind of question:

Input

There will be at most 10 test cases. Each case begins with two integers n and Q (1 <= n <= 20,000, 2 <= Q <= 40,000). Each of the following lines contains either a fact or a question, formatted as stated above. The k parameter in the questions will be a positive integer not greater than 15, and the v parameter in the facts will be a non-negative integer less than 220. The last case is followed by n=Q=0, which should not be processed.

Output

For each test case, print the case number on its own line, then the answers, one on each one. If you can't deduce the answer for a particular question, from the facts I provide you before that question, print "I don't know.", without quotes. If the i-th fact (don't count questions) cannot be consistent with all the facts before that, print "The first i facts are conflicting.", then keep silence for everything after that (including facts and questions). Print a blank line after the output of each test case.

Sample Input

2 6 I 0 1 3 Q 1 0 Q 2 1 0 I 0 2 Q 1 1 Q 1 0 3 3 I 0 1 6 I 0 2 2 Q 2 1 2 2 4 I 0 1 7 Q 2 0 1 I 0 1 8 Q 2 0 1 0 0

Sample Output

Case 1: I don't know. 3 1 2 Case 2: 4 Case 3: 7 The first 2 facts are conflicting.

Hint

chenrui

Source

2009 Asia Wuhan Regional Contest Hosted by

提交代码