using System;
using System.Text.RegularExpressions;

public class Test
{
	public static void Main()
	{
		string[] inp = new string[] {
			"Some words",
			"Some words and some other words",
			"Some words, more words and some other words",
			"Some words, more words, and some other words" 
		};
		foreach (string s in inp) {
			string[] phrases = (Regex.Split(s, @"(?:,\s*|\s+)and\s+|,\s*"));
			Console.WriteLine(string.Join("\n", phrases));
		}
	}
}