Jabber ID

题意翻译

题目大意 一个地址由<username>@<hostname>[/resource]组成，其中[/resource]可以被省略。 <username>字段允许大写、小写字母，数字、下划线，其长度应在1到16。 <hostname>字段允许用.来分隔。每一段的要求同<username>字段，分隔出的每一部分长度在1到16，<hostname字段的总长度在1到32。 <resource>字段要求同<username>字段。 给出一个地址，询问是否合法。 输入输出格式 输入格式 一行，一个字符串，表示一个地址（保证地址的字符的ASCII在33到127间），地址长度不超过100字符 输出格式 一行，如果合法输出YES，否则输出NO

题目描述

Jabber ID on the national Berland service «Babber» has a form <username>@<hostname>\[/resource\], where - <username> — is a sequence of Latin letters (lowercase or uppercase), digits or underscores characters «\_», the length of <username> is between 1 and 16, inclusive. - <hostname> — is a sequence of word separated by periods (characters «.»), where each word should contain only characters allowed for <username>, the length of each word is between 1 and 16, inclusive. The length of <hostname> is between 1 and 32, inclusive. - <resource> — is a sequence of Latin letters (lowercase or uppercase), digits or underscores characters «\_», the length of <resource> is between 1 and 16, inclusive. The content of square brackets is optional — it can be present or can be absent. There are the samples of correct Jabber IDs: mike@codeforces.com, 007@en.codeforces.com/contest. Your task is to write program which checks if given string is a correct Jabber ID.

输入输出格式

输入格式

The input contains of a single line. The line has the length between 1 and 100 characters, inclusive. Each characters has ASCII-code between 33 and 127, inclusive.

输出格式

Print YES or NO.

输入输出样例

输入样例 #1

mike@codeforces.com

输出样例 #1

YES

输入样例 #2

john.smith@codeforces.ru/contest.icpc/12

输出样例 #2

NO