using System;
 
public class Test
{
	public static void Main()
	{
	string start = "data-token=";
      string end = " href";
 
      string source = "<a class='bizLink' data-token='-iUzEhgdscgbpj5VMi5zoh54FTeFt8M4mj5nsiodxR5VzZOhniodpj6nFQg0nce3MhUxFSgdxjM4JjUVzZuNu8o0sREnFSUzISUXzZWh4iodGQfdxR5VzZWh4iodGQfhli6fnce_=1\" href='";
 
      int firstTag = source.IndexOf(start);
      int lastTag = source.IndexOf(end, firstTag );
      int startIndex = firstTag + start.Length +1;
      int endIndex = lastTag;
      string authenticityToken = source.Substring(startIndex, endIndex - startIndex -1);
      Console.Write(authenticityToken);
	}
}

dXNpbmcgU3lzdGVtOwoKcHVibGljIGNsYXNzIFRlc3QKewoJcHVibGljIHN0YXRpYyB2b2lkIE1haW4oKQoJewoJc3RyaW5nIHN0YXJ0ID0gImRhdGEtdG9rZW49IjsKICAgICAgc3RyaW5nIGVuZCA9ICIgaHJlZiI7CgogICAgICBzdHJpbmcgc291cmNlID0gIjxhIGNsYXNzPSdiaXpMaW5rJyBkYXRhLXRva2VuPSctaVV6RWhnZHNjZ2JwajVWTWk1em9oNTRGVGVGdDhNNG1qNW5zaW9keFI1VnpaT2huaW9kcGo2bkZRZzBuY2UzTWhVeEZTZ2R4ak00SmpVVnpadU51OG8wc1JFbkZTVXpJU1VYelpXaDRpb2RHUWZkeFI1VnpaV2g0aW9kR1FmaGxpNmZuY2VfPTFcIiBocmVmPSciOwoKICAgICAgaW50IGZpcnN0VGFnID0gc291cmNlLkluZGV4T2Yoc3RhcnQpOwogICAgICBpbnQgbGFzdFRhZyA9IHNvdXJjZS5JbmRleE9mKGVuZCwgZmlyc3RUYWcgKTsKICAgICAgaW50IHN0YXJ0SW5kZXggPSBmaXJzdFRhZyArIHN0YXJ0Lkxlbmd0aCArMTsKICAgICAgaW50IGVuZEluZGV4ID0gbGFzdFRhZzsKICAgICAgc3RyaW5nIGF1dGhlbnRpY2l0eVRva2VuID0gc291cmNlLlN1YnN0cmluZyhzdGFydEluZGV4LCBlbmRJbmRleCAtIHN0YXJ0SW5kZXggLTEpOwogICAgICBDb25zb2xlLldyaXRlKGF1dGhlbnRpY2l0eVRva2VuKTsKCX0KfQ==