/* package whatever; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;
import java.util.regex.Pattern;
import java.util.regex.Matcher;

/* 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
	{
		String[] aStr = {"9547235617/7865421341", "6547235617/5865421341", "4547235617/9865421341"};
		
		for(String str: aStr) {
		    Matcher matcher = Pattern.compile("(?<=^|\\/)(?:\\b[7-9]\\d{9}\\b)?").matcher(str);
		    while(matcher.find()){
		        if(matcher.group().equals("")) {
		            System.out.print("No number available" + "\n");
		        } else {
		            System.out.print(matcher.group() + "\n");
		        }
		    }
		}
	}
}