{"trustable":true,"sections":[{"title":"","value":{"format":"HTML","content":"\u003cdiv class\u003d\"problem_par\"\u003e\u003cdiv class\u003d\"problem_par_normal\"\u003eNow you are asked for help by the organizers of the Winter Olympic Games 2014, \r\nwhich, as you know, will be held in Yekaterinozavodsk. And although there are \r\nstill 6 years ahead, the first sport facility is already put into operation. \r\nIt is the track for the skiing race.\r\n\u003c/div\u003e\u003c/div\u003e\u003cdiv class\u003d\"problem_par\"\u003e\u003cdiv class\u003d\"problem_par_normal\"\u003eIt was decided to construct a huge screen near the tribunes, which would show \r\nthe name of a current leader during the race. It is known, that only the first \r\n\u003ci\u003eN\u003c/i\u003e letters of English alphabet are used to write the names of the sportsmen, and \r\neach of the \u003ci\u003eN\u003c/i\u003e letters should appear in each name exactly once. Technically,\r\nthe screen looks like a word with letters from the English alphabet; each of these letters can either shine or stay dark. The organizers call the word \r\n“universal” if the screen based on it can display any possible name of a \r\nsportsman (possibly with some holes between neighboring letters). The governor \r\nproposed some word for the screen. You should tell whether this word is \r\nuniversal.\r\n\u003c/div\u003e\u003c/div\u003e"}},{"title":"Input","value":{"format":"HTML","content":"\u003cdiv class\u003d\"problem_par\"\u003e\u003cdiv class\u003d\"problem_par_normal\"\u003eThe first line contains an integer \u003ci\u003eN\u003c/i\u003e (1\u0026nbsp;≤\u0026nbsp;\u003ci\u003eN\u003c/i\u003e\u0026nbsp;≤\u0026nbsp;26). The second line contains \r\na word to check, consisting of lowercase English letters. The word can contain \r\nonly first \u003ci\u003eN\u003c/i\u003e letters of the alphabet. The length of the word doesn\u0027t exceed 300.\r\n\u003c/div\u003e\u003c/div\u003e"}},{"title":"Output","value":{"format":"HTML","content":"\u003cdiv class\u003d\"problem_par\"\u003e\u003cdiv class\u003d\"problem_par_normal\"\u003eOutput “YES”, if the word, proposed by governor, is universal and “NO” otherwise.\r\n\u003c/div\u003e\u003c/div\u003e"}},{"title":"Sample","value":{"format":"HTML","content":"\u003ctable class\u003d\u0027vjudge_sample\u0027\u003e\n\u003cthead\u003e\n \u003ctr\u003e\n \u003cth\u003eInput\u003c/th\u003e\n \u003cth\u003eOutput\u003c/th\u003e\n \u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\u003cpre\u003e3\r\nabacaba\r\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003eYES\r\n\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003cbr\u003e\u003ctable class\u003d\u0027vjudge_sample\u0027\u003e\n\u003cthead\u003e\n \u003ctr\u003e\n \u003cth\u003eInput\u003c/th\u003e\n \u003cth\u003eOutput\u003c/th\u003e\n \u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\u003cpre\u003e3\r\nabcba\r\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003eNO\r\n\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n"}}]}