This is an interactive problem. The jury has a string (s) consisting of lowercase Latin letters. The following constraints apply to this string: the string has an odd length that does not exceed (99); the string consists only of the characters " a " and " b ". There is also a string (t), which is initially empty. Then, (|s|) steps happen. During the (i)-th step, the following events occur: first, the jury tells you the character (s_i) and appends it to the end of the string (t); then, you may swap any two characters in (t), or do nothing. Your task is to ensure that after the (|s|)-th step, the string (t) is a palindrome. The interactive interaction starts immediately. During each step, your program will receive one character — the next character of the string (s) or " 0 " (zero) if the string has ended. If the character " 0 " is received, your program must terminate immediately. After receiving (s_{i}), you must output the positions of the characters to be swapped, that is, two integers (l) and (r) ((1 \le l,r \le i)) or, if you do not want to swap characters, then " 0 0 ". If your program makes an invalid operation, for example, by trying to swap characters from non-existing positions, or the resulting string (t) is not a palindrome, the jury program will print one character " X " on a separate line. If your program receives " X " as the response, it should terminate immediately ; otherwise, the verdict of your submission will be undefined. The interactor in this problem is not adaptive , meaning that the string (s) does not change during the interaction. After each output request, do not forget to output a newline and flush the output buffer. Otherwise, you will receive a verdict of " Idleness limit exceeded ". To do this, use: fflush(stdout) or cout.flush() in C++ ; System.out.flush() in Java ; sys.stdout.flush() in Python ; refer to the documentation for other languages. Hack format F