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

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

/* 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
	{
		
		final String regex = "(?!(?:(?=XYZ)|(?<=X)(?=YZ)|(?<=XY)(?=Z))).";
		final String string = "abXYxyzXYZabXasdfggXYZ";
		final String subst = "+";
		
		final Pattern pattern = Pattern.compile(regex);
		final Matcher matcher = pattern.matcher(string);
		
		// The substituted value will be contained in the result variable
		final String result = matcher.replaceAll(subst);
		
		System.out.println("Substitution result: " + result);

	}
}