using System.Collections.Generic;
public static void Main()
List<string> stringList = new List<string>()
"2015-03-08 10:30:00 /user841/column-width",
"2015-03-08 10:30:01 /user849/connect",
"2015-03-08 10:30:01 /user262/open-level2-price",
"2015-03-08 10:30:01 /user839/open-detailed-quotes"
List<string> outputList = new List<string>();
foreach(string s in stringList)
outputList.Add(s.Split('/').Last());
Console.WriteLine(string.Join("\n", outputList));