using System;
using System.Linq;
class Program
{
static void Main() {
int[] array1 = {1, 2, 3, 4};
Console.WriteLine(string.Join(", ", array1));
var array2 = array1.Prepend(0);
Console.WriteLine(string.Join(" ", array2));
var array3 = array2.Prepend(-1);
Console.WriteLine(string.Join(", ", array3));
}
}
/*
run:
1, 2, 3, 4
0 1 2 3 4
-1, 0, 1, 2, 3, 4
*/