using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text.RegularExpressions;
public class Test
{
public static void Main()
{
string pattern = @"[.&@]+(?=.*@)";
string input = "username@middle&something.else@company.com";
string result = Regex.Replace(input, pattern, string.Empty);
Console.WriteLine(result);
}
}
dXNpbmcgU3lzdGVtOwp1c2luZyBTeXN0ZW0uQ29sbGVjdGlvbnMuR2VuZXJpYzsKdXNpbmcgU3lzdGVtLklPOwp1c2luZyBTeXN0ZW0uTGlucTsKdXNpbmcgU3lzdGVtLlRleHQuUmVndWxhckV4cHJlc3Npb25zOwoKcHVibGljIGNsYXNzIFRlc3QKewoJcHVibGljIHN0YXRpYyB2b2lkIE1haW4oKQoJewoJCXN0cmluZyBwYXR0ZXJuID0gQCJbLiZAXSsoPz0uKkApIjsKCQlzdHJpbmcgaW5wdXQgPSAidXNlcm5hbWVAbWlkZGxlJnNvbWV0aGluZy5lbHNlQGNvbXBhbnkuY29tIjsKCQlzdHJpbmcgcmVzdWx0ID0gUmVnZXguUmVwbGFjZShpbnB1dCwgcGF0dGVybiwgc3RyaW5nLkVtcHR5KTsKCQlDb25zb2xlLldyaXRlTGluZShyZXN1bHQpOwoJfQp9