import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.*;
import java.lang.*;
import java.io.*;
 
 
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		String strings[] = { "1","2, 3","6, 7, 4",",5","5 6 0","4,5" };
		String regex = "^\\d+(?:, \\d+)*$";
		Pattern pattern = Pattern.compile(regex);
 
	    for (String str : strings) {
	    	Matcher matcher = pattern.matcher(str);
	    	if (matcher.find()) {
		    	System.out.println(matcher.group(0) + " - ok!");
	    	} else {
		    	System.out.println(str + " - bad!");
		    }
		}
	}
}

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