(a*)*b on a^n

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class Main {
        public static void main(String[] args) {
                String regex = "(a*)*b";
                String haystack = "a";
                for( int i = 1;i < 30; i++ ){
                long start = System.nanoTime();
                Pattern pattern = Pattern.compile( regex );
                Matcher matcher = pattern.matcher( haystack );
                matcher.find();
                long end = System.nanoTime();
                System.out.println("On " + haystack + ", .find run in " + (end - start) + " nanoseconds.");
                haystack = haystack + "a";
                }
        }
}