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

import java.util.*;
import java.lang.*;
import java.io.*;
import java.util.regex.*;
/* 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 s = "@test, @{@test2, dasdas. @test3?} @test4? @test5!";
		Pattern pattern = Pattern.compile("@(\\w+)");
		Matcher matcher = pattern.matcher(s);
		while (matcher.find()){
			System.out.println(matcher.group(1)); 
		} 
	}
}