using System;
using System.Collections.Generic;
using System.Linq;

public class Test
{
	public static void Main()
	{
		Console.WriteLine("Testing with 'xxx yy zzzz'");
    	foreach (var pair in SplitIntoPairsByWhitespace("xxx yy zzzz"))
		{
    	    Console.WriteLine(string.Join(", ", pair));
		}
		Console.WriteLine("Testing with 'a b c d'");
    	foreach (var pair in SplitIntoPairsByWhitespace("a b c d"))
    	{
    	    Console.WriteLine(string.Join(", ", pair));
		}
	}
	public static List<string[]> SplitIntoPairsByWhitespace(string text) 
	{
		var chunks = text.Split();
    	var result = new List<string[]>();
        for (var i=0; i<chunks.GetLength(0) - 1; i++)
        {
        	var first = new List<string>();
        	for (var j=0; j <= i; j++)
        	    first.Add(chunks[j]);
        	var second = new List<string>();
        	for (var j=i+1; j < chunks.GetLength(0); j++)
        	    second.Add(chunks[j]);
        	result.Add(new[] {string.Join(" ", first), string.Join(" ", second)});
        }
        return result;
	}
}