/* 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 p = Pattern.compile("(.*)_(0?\\d|1[0-7])\\.png");
		for (int i = 0 ; i != 10 ; i++) {
			String s = "hello_0"+i+".png";
			Matcher m = p.matcher(s);
			System.out.println(s+":"+m.find());
		}
		for (int i = 0 ; i != 20 ; i++) {
			String s = "hello_"+i+".png";
			Matcher m = p.matcher(s);
			System.out.println(s+":"+m.find());
		}
	}
}

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