/* package whatever; // don't place package name! */
 
import java.util.*;
import java.util.regex.*;
import java.lang.*;
import java.io.*;
 
/* 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
	{
        Pattern regex = Pattern.compile("by_(.*)_on");
        String str = "Files_by_wesasegeaazedude_on_January_26.jpg";
        Matcher m = regex.matcher(str);
        if (m.find()) {
            String res = m.group(1);
            System.out.println(res);
        }
    }
}

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