B"This problem is different with easy version only by constraints on total answers length It is an interactive problem Venya joined a tour to the madhouse, in which orderlies play with patients the following game. Orderlies pick a string s of length n , consisting only of lowercase English letters. The player can ask two types of queries: The player can ask no more than 3 queries of the first type. To make it easier for the orderlies, there is an additional limitation: the total number of returned substrings in all queries of the first type must not exceed <= ft lceil 0.777(n+1)^2 right rceil ( lceil x rceil is x rounded up). Venya asked you to write a program, which will guess the string by interacting with the orderlies' program and acting by the game's rules. Your program should immediately terminate after guessing the string using a query of the second type. In case your program guessed the string incorrectly, or it violated the game rules, it will receive verdict Wrong answer. Note that in every test case the string is fixed beforehand and will not change during the game, which means that the interactor is not adaptive. First line contains number n ( 1 <= n <= 100 ) -- the length of the picked string. You start the interaction by reading the number n . To ask a query about a substring from l to r inclusively ( 1 <= l <= r <= n ), you should output ? l r on a separate line. After this, all substrings of s[l..r] will be returned in random order, each substring exactly once. In every returned substring all characters will be randomly shuffled. In the case, if you ask an incorrect query, ask more than 3 queries of the first type or there will be more than <= ft lceil 0.777(n+1)^2 right rceil substrings returned in total, you will receive verdict Wrong answer. To guess the string s , you should output ! s on a separate line. After printing each query, do not f"...