using System.Text.RegularExpressions;
using System.Globalization;
public static void Main()
var input2 = @"\u0410\u041b\u0415\u041a\u0421\u0410\u041d\u0414\u0420";
var result = Regex.Replace(
@"\\[Uu]([0-9A-Fa-f]{4})",
(char)ushort.Parse(m.Groups[1].Value, NumberStyles.AllowHexSpecifier)));
Console.WriteLine(result);