/* package whatever; // don't place package name! */
 
import java.util.*;
import java.util.stream.*;
import java.lang.*;
import java.io.*;
 
/* 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 order = "A-G / F-B / A-B / A-F / G-B / G-F";
		String[] stack = { "B", "F", "A", "G" };
 
		Set<List<String>> pairs = Arrays.stream(order.split(" / "))
		        .map(p -> p.split("-"))
		        .map(Arrays::asList)
		        .collect(Collectors.toSet());
 
		Arrays.sort(stack, (a, b) ->
		        pairs.contains(Arrays.asList(a, b)) ? -1 :
		        pairs.contains(Arrays.asList(b, a)) ? 1 :
		        0
		);
 
		System.out.println(Arrays.toString(stack));
	}
}

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