{"trustable":false,"sections":[{"title":"","value":{"format":"HTML","content":"\u003cstyle type\u003d\"text/css\"\u003e\r\nh1,h2,h3,h4,h5,h6{margin-bottom:0;}div.textBG p{margin: 0 0 0.0001pt;}\u003c/style\u003e\r\n\u003cp\u003e\r\n\t\u0026nbsp;\u003c/p\u003e\r\n\u003cdiv style\u003d\"clear:both\"\u003e\r\n\t\u0026nbsp;\u003c/div\u003e\r\n\u003ch1\u003e\r\n\t\u0026nbsp;\u003c/h1\u003e\r\n\u003cbr clear\u003d\"ALL\" /\u003e\r\n\u003ccenter\u003e\r\n\t\u003ctable bgcolor\u003d\"#0060F0\"\u003e\r\n\t\t\u003ctbody\u003e\r\n\t\t\t\u003ctr\u003e\r\n\t\t\t\t\u003ctd\u003e\r\n\t\t\t\t\t\u003ch1\u003e\r\n\t\t\t\t\t\t\u0026nbsp;\u003c/h1\u003e\r\n\t\t\t\t\u003c/td\u003e\r\n\t\t\t\u003c/tr\u003e\r\n\t\t\u003c/tbody\u003e\r\n\t\u003c/table\u003e\r\n\u003c/center\u003e\r\n\u003cp\u003e\r\n\tGiven a string containing only alpha-numerals (\u003ctt\u003e0-9\u003c/tt\u003e, \u003ctt\u003eA-Z\u003c/tt\u003e and \u003ctt\u003ea-z\u003c/tt\u003e) you have to count the frequency (the number of times the character is present) of all the characters and report only those characters whose frequency is a prime number. A prime number is a number, which is divisible by exactly two different integers. Some examples of prime numbers are \u003cb\u003e2\u003c/b\u003e, \u003cb\u003e3\u003c/b\u003e, \u003cb\u003e5\u003c/b\u003e, \u003cb\u003e7\u003c/b\u003e, \u003cb\u003e11\u003c/b\u003e etc.\u003c/p\u003e\r\n\u003cp\u003e\r\n\t\u0026nbsp;\u003c/p\u003e\r\n\u003ch2\u003e\r\n\t\u003cfont color\u003d\"#0070E8\"\u003e\u003ca name\u003d\"SECTION0001001000000000000000\"\u003e Input\u003c/a\u003e\u0026nbsp;\u003c/font\u003e\u003c/h2\u003e\r\n\u003cp\u003e\r\n\t\u0026nbsp;\u003c/p\u003e\r\n\u003cdiv align\u003d\"CENTER\"\u003e\r\n\u003c!-- MATH\r\n $\\epsfbox{p10789.eps}$\r\n --\u003e\t\u003cimg align\u003d\"BOTTOM\" alt\u003d\"\\epsfbox{p10789.eps}\" border\u003d\"0\" height\u003d\"383\" src\u003d\"http://uva.onlinejudge.org/external/107/p10789.jpg\" width\u003d\"479\" /\u003e\u003c/div\u003e\r\n\u003cp\u003e\r\n\tThe first line of the input is an integer \u003cspan class\u003d\"MATH\"\u003e\u003ci\u003eT\u003c/i\u003e\u003c/span\u003e (\u003c!-- MATH\r\n $0 \u003c T \u003c 201$\r\n --\u003e\u003cspan class\u003d\"MATH\"\u003e0 \u0026lt; \u003ci\u003eT\u003c/i\u003e \u0026lt; 201\u003c/span\u003e) that indicates how many sets of inputs are there. Each of the next \u003cspan class\u003d\"MATH\"\u003e\u003ci\u003eT\u003c/i\u003e\u003c/span\u003e lines contains a single set of input.\u003c/p\u003e\r\n\u003cp\u003e\r\n\tThe input of each test set is a string consisting alpha-numerals only. The length of this string is positive and less than \u003cb\u003e2001\u003c/b\u003e.\u003c/p\u003e\r\n\u003cp\u003e\r\n\t\u0026nbsp;\u003c/p\u003e\r\n\u003ch2\u003e\r\n\t\u003cfont color\u003d\"#0070E8\"\u003e\u003ca name\u003d\"SECTION0001002000000000000000\"\u003e Output\u003c/a\u003e\u0026nbsp;\u003c/font\u003e\u003c/h2\u003e\r\n\u003cp\u003e\r\n\tFor each set of input produce one line of output. This line contains the serial of output followed by the characters whose frequency in the input string is a prime number. These characters are to be sorted in lexicographically ascending order. Here ``lexicographically ascending\u0026quot; means ascending in terms of the \u003cb\u003eASCII\u003c/b\u003e values. Look at the output for sample input for details. If none of the character frequency is a prime number, you should print `\u003ctt\u003eempty\u003c/tt\u003e\u0026#39; (without the quotes) instead.\u003c/p\u003e\r\n\u003cp\u003e\r\n\t\u0026nbsp;\u003c/p\u003e\r\n\u003ch2\u003e\r\n\t\u003cfont color\u003d\"#0070E8\"\u003e\u003ca name\u003d\"SECTION0001003000000000000000\"\u003e Sample Input\u003c/a\u003e\u0026nbsp;\u003c/font\u003e\u003c/h2\u003e\r\n\u003cp\u003e\r\n\t\u0026nbsp;\u003c/p\u003e\r\n\u003cpre\u003e\r\n3\r\n\u003cspan data-scayt_word\u003d\"ABCC\" data-scaytid\u003d\"1\"\u003eABCC\u003c/span\u003e\r\n\u003cspan data-scayt_word\u003d\"AABBBBDDDDD\" data-scaytid\u003d\"2\"\u003eAABBBBDDDDD\u003c/span\u003e\r\n\u003cspan data-scayt_word\u003d\"ABCDFFFF\" data-scaytid\u003d\"3\"\u003eABCDFFFF\u003c/span\u003e\r\n\u003c/pre\u003e\r\n\u003cp\u003e\r\n\t\u0026nbsp;\u003c/p\u003e\r\n\u003ch2\u003e\r\n\t\u003cfont color\u003d\"#0070E8\"\u003e\u003ca name\u003d\"SECTION0001004000000000000000\"\u003e Sample Output\u003c/a\u003e\u0026nbsp;\u003c/font\u003e\u003c/h2\u003e\r\n\u003cp\u003e\r\n\t\u0026nbsp;\u003c/p\u003e\r\n\u003cpre\u003e\r\nCase 1: C\r\nCase 2: AD\r\nCase 3: empty\r\n\u003c/pre\u003e\r\n\u003cp\u003e\r\n\t\u0026nbsp;\u003c/p\u003e\r\n\u003cp\u003e\r\n\t\u0026nbsp;\u003c/p\u003e\r\n\u003chr /\u003e\r\n\u003caddress\u003e\r\n\tMiguel \u003cspan data-scayt_word\u003d\"Revilla\" data-scaytid\u003d\"4\"\u003eRevilla\u003c/span\u003e 2004-12-10\u003c/address\u003e"}}]}