using System;
using System.Text.RegularExpressions;
public class Test
{
public static void Main()
{
string str = "Only 'together' can we turn him to the 'dark side' of the Force";
string result = Regex.Replace(str, @"('[^']*\bdark\b[^']*')|'[^']*'", "$1");
Console.WriteLine(result);
Console.ReadLine();
}
}
dXNpbmcgU3lzdGVtOwp1c2luZyBTeXN0ZW0uVGV4dC5SZWd1bGFyRXhwcmVzc2lvbnM7CiAKcHVibGljIGNsYXNzIFRlc3QKewpwdWJsaWMgc3RhdGljIHZvaWQgTWFpbigpCnsKc3RyaW5nIHN0ciA9ICJPbmx5ICd0b2dldGhlcicgY2FuIHdlIHR1cm4gaGltIHRvIHRoZSAnZGFyayBzaWRlJyBvZiB0aGUgRm9yY2UiOwpzdHJpbmcgcmVzdWx0ID0gUmVnZXguUmVwbGFjZShzdHIsIEAiKCdbXiddKlxiZGFya1xiW14nXSonKXwnW14nXSonIiwgIiQxIik7CkNvbnNvbGUuV3JpdGVMaW5lKHJlc3VsdCk7CkNvbnNvbGUuUmVhZExpbmUoKTsKfQp9