import java.util.*;

import java.io.*;

import java.net.*;

public class gatherfullids {

  public static void main(String[] args) throws Exception {

    PrintWriter out = new PrintWriter(new File("fullctrpids.csv"));

    for (int i = 0; i < 9455; i+=50) {

      String source = getURLSource("https://clinicaltrialsapi.cancer.gov/v1/clinical-trials?size=50&from=" + i + "&study_protocol_type=interventional&include=nct_id");

      int index = source.indexOf("NCT");

      while (index != -1) {

        out.println(source.substring(index, index + 11));

        index = source.indexOf("NCT", index+1);

      }

    }

    out.close();

  }

  public static String getURLSource(String url) throws IOException

    {

        URL urlObject = new URL(url);

        URLConnection urlConnection = urlObject.openConnection();

        urlConnection.setRequestProperty("User-Agent", "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.11 (KHTML, like Gecko) Chrome/23.0.1271.95 Safari/537.11");

        try {

        return toString(urlConnection.getInputStream());}catch(Exception e) {return "";}

    }

  private static String toString(InputStream inputStream) throws IOException

    {

        try (BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream, "UTF-8")))

        {

            String inputLine;

            StringBuilder stringBuilder = new StringBuilder();

            while ((inputLine = bufferedReader.readLine()) != null)

            {

                stringBuilder.append(inputLine);

            }

            return stringBuilder.toString();

        }

    }

}