{"raw_statement":[{"iden":"problem statement","content":"**This is an interactive task.**\nYou have to guess a secret password $S$. A password is a nonempty string whose length is at most $L$. The characters of a password can be lowercase and uppercase english letters (a, b, ... , z, A, B, ... , Z) and digits (0, 1, ... , 9).\nIn order to guess the secret password $S$ you can ask queries. A query is made of a valid password $T$, the answer to such query is the edit distance between $S$ and $T$ (the operations considered for the edit distance are: removal, insertion, substitution). You can ask at most $Q$ queries.\n**Note**: For a definition of edit distance (with operations: removal, insertion, substitution), see [this wikipedia page](https://en.wikipedia.org/w/index.php?title=Levenshtein_distance&oldid=954598393)."},{"iden":"constraints","content":"*   $L = 128$\n*   $Q = 850$\n*   The secret password $S$ is chosen before the beginning of the interaction."},{"iden":"interaction","content":"To ask a query, print on Standard Output (with a newline at the end)\n\n? $T$\n\nThe string $T$ must be a valid password.\nThe answer $ans$ to each query shall be read from Standard Input in the form:\n\n$ans$\n\nAs soon as you have determined the hidden password $S$, you should print on Standard Output (with a newline at the end)\n\n! $S$\n\nand terminate your program."},{"iden":"judgement","content":"*   **After each output, you must flush Standard Output.** Otherwise you may get `TLE`.\n*   After you print (your guess of) the hidden password, the program must be terminated immediately. Otherwise, the behavior of the judge is undefined.\n*   If the password you have determined is wrong, you will get `WA`.\n*   If you ask a malformed query (for example because the string is not a valid password, or you forget to put `?`) or if your program crashes or if you ask more than $Q$ queries, the behavior of the judge is undefined (it does not necessarily give `WA`)."},{"iden":"samples","content":"In the only sample testcase of this problem the hidden password is `Atcod3rIsGreat`.\nThe following one is an example of interaction if $S=$`Atcod3rIsGreat`.\n\nInput\n\nOutput\n\n$\\texttt{? AtcoderIsBad}$\n\n$5$\n\n$\\texttt{? AtcoderIsGreat}$\n\n$1$\n\n$\\texttt{! Atcod3rIsGreat}$"}],"translated_statement":null,"sample_group":[],"show_order":["default"],"formal_statement":null,"simple_statement":null,"has_page_source":true}