/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		Set<String> set = new HashSet<String>();
		  String line = "a+(b * 6) <= cat*45 && cat = dog";
	      String pattern = "\\b([A-Za-z]\\w*)\\b";
 
	      // Create a Pattern object
	      Pattern r = Pattern.compile(pattern);
 
	      // Now create matcher object.
	      Matcher m = r.matcher(line);
	      while (m.find()) {
	         set.add(m.group() );
      	  }
      	  System.out.println(set);
	}
}

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