CF34C.Page Numbers

«Bersoft» company is working on a new version of its most popular text editor — Bord 2010. Bord, like many other text editors, should be able to print out multipage documents. A user keys a sequence of the document page numbers that he wants to print out (separates them with a comma, without spaces).

Your task is to write a part of the program, responsible for «standardization» of this sequence. Your program gets the sequence, keyed by the user, as input. The program should output this sequence in format _l_1-_r_1,_l_2-_r_2,...,l__k-r__k, where r__i + 1 < l__i + 1 for all i from 1 to k - 1, and l__i ≤ r__i. The new sequence should contain all the page numbers, keyed by the user, and nothing else. If some page number appears in the input sequence several times, its appearances, starting from the second one, should be ignored. If for some element i from the new sequence l__i = r__i, this element should be output as l__i, and not as «l__i - l__i».

For example, sequence 1,2,3,1,1,2,6,6,2 should be output as 1-3,6.

«Bersoft» 公司正在开发其最受欢迎的文本编辑器——Bord 2010 的新版本。与许多其他文本编辑器一样，Bord 也应支持打印多页文档。用户通过键盘输入希望打印的文档页码序列（页码之间用逗号分隔，不包含空格）。

你的任务是编写该程序中负责对这一序列进行「标准化」的部分。你的程序将接收用户输入的页码序列作为输入，并输出标准化后的序列，格式为：
$l_1$-$r_1$,$l_2$-$r_2$,...,$l_k$-$r_k$，
其中对所有 $i$（$1 \le i \le k-1$）均满足 $r_i+1 < l_{i+1}$，且对所有 $i$（$1 \le i \le k$）均满足 $l_i \le r_i$。
新序列必须包含用户输入的所有页码（去重后），且不能包含任何其他页码。若某个页码在输入序列中出现多次，则仅保留第一次出现，其余重复项应被忽略。若新序列中某一项满足 $l_i = r_i$，则该项应仅输出为 $l_i$，而不得输出为 «$l_i$-$l_i$»。

例如，输入序列 1,2,3,1,1,2,6,6,2 应输出为 1-3,6。

The only line contains the sequence, keyed by the user. The sequence contains at least one and at most 100 positive integer numbers. It's guaranteed, that this sequence consists of positive integer numbers, not exceeding 1000, separated with a comma, doesn't contain any other characters, apart from digits and commas, can't end with a comma, and the numbers don't contain leading zeroes. Also it doesn't start with a comma or contain more than one comma in a row.

唯一的一行包含用户输入的序列。该序列至少包含一个、至多包含 100 个正整数。保证该序列由不超过 1000 的正整数组成，各数之间以逗号分隔；除数字和逗号外不包含其他任何字符；不以逗号开头；不以逗号结尾；数字不含前导零；且不会出现连续两个或以上的逗号。

Output the sequence in the required format.

按要求的格式输出该序列。