using System;
using System.Linq;
public class Program
{
public static void Main()
{
string[,] rectangularArray = new string[3, 3] {
{"a", "b", "c"},
{"d", "e", "f"},
{"g", "h", "i"}};
var result = rectangularArray.Cast<object>().ToArray();
Console.Write(string.Join(", ", result));
}
}
/*
run:
a, b, c, d, e, f, g, h, i
*/