Unable to read pdf text as some text in inputbox

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C#

itextsharp

I have a pdf file I need to compare a Number with PDF Text if it matched then I will save the pdf file. The problem is I am not able to read some text which is in input box. I just need to read "LICI0318245279" from following pdf file. here is the link : https://www.dropbox.com/s/g45usoyrz4vua9r/3.pdf

PdfReader pdfReader = new PdfReader(Server.MapPath("1.pdf"));
string TempFilename = Path.GetTempFileName();
AcroFields pdfFormFields = pdfReader.AcroFields;
foreach (KeyValuePair<string, AcroFields.Item> kvp in pdfFormFields.Fields)
{   
  string fieldName = kvp.Key.ToString();
  string fieldValue = pdfFormFields.GetField(kvp.Key.ToString());
  Console.WriteLine(fieldName + " " + fieldValue);
}

pdfReader.Close();

I have also tried to read all fields from pdf but in result I am not getting any field or its value.