C# Single line
For each string\n  * Split by \'@\'\n  * Remove all after the first \'+\' in the local name\n  * Remove all dots in the local name\n  * Concat the results back 
* For each string\n  * Split by \'@\'\n  * Remove all after the first \'+\' in the local name\n  * Remove all dots in the local name\n  * Concat the results back together to 1 string\n* Return the distinct elements\n```csharp\npublic int NumUniqueEmails(string[] emails) \n\t=> emails.Select(x => x.Split(\'@\')).Select(split => split[0].Split(\'+\')[0].Replace(".", "") + "@" + split[1]).Distinct().Count();\n```
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