/* 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 = "one=1&two=2&=3&tr=";
		Pattern patt = Pattern.compile("(?:\\w+=\\w*|=\\w+)(?:&(?:\\w+=\\w*|=\\w+))*");
		Matcher m = patt.matcher(s);
		if(m.matches()) {
			System.out.println("true");
		} else {
			System.out.println("false");
		}
			 
		
	}
}