CF21A.Jabber ID

Jabber ID on the national Berland service «Babber» has a form @[/resource], where

• — is a sequence of Latin letters (lowercase or uppercase), digits or underscores characters «_», the length of is between 1 and 16, inclusive.
• — is a sequence of word separated by periods (characters «.»), where each word should contain only characters allowed for , the length of each word is between 1 and 16, inclusive. The length of is between 1 and 32, inclusive.
• — is a sequence of Latin letters (lowercase or uppercase), digits or underscores characters «_», the length of 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: [email protected], [email protected]/contest.

Your task is to write program which checks if given string is a correct Jabber ID.

国家贝尔兰服务「Babber」上的 Jabber ID 格式为 <username>@<hostname>[/resource]，其中：

• <username> —— 是由拉丁字母（大小写均可）、数字或下划线字符 \_ 组成的序列，<username> 的长度在 1 到 16（含）之间。
• <hostname> —— 是由点号（字符 .）分隔的若干单词组成的序列，每个单词仅能包含与 <username> 相同的字符，且每个单词的长度在 1 到 16（含）之间；整个 <hostname> 的长度在 1 到 32（含）之间。
• <resource> —— 是由拉丁字母（大小写均可）、数字或下划线字符 \_ 组成的序列，<resource> 的长度在 1 到 16（含）之间。

方括号 [ ] 中的内容是可选的——可以存在，也可以不存在。

以下是合法 Jabber ID 的示例：[email protected]，[email protected]/contest。

你的任务是编写一个程序，判断给定字符串是否为合法的 Jabber ID。

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.

输入仅包含一行。该行长度在 1 到 100 个字符之间（含端点）。每个字符的 ASCII 码在 33 到 127 之间（含端点）。

Print YES or NO.

输出 YES 或 NO。