using System;

using System.Collections.Generic;

using System.Linq;

​

public class Program

{

    public static void Main()

    {

        var chars = Enumerable

            .Range(0, 26)

            .Select(x => $"\"{(char)('a' + x)}\"");

        Console.WriteLine($"「{string.Join(",", chars)}」");

        // or

        var strings = new string[26];

        for (var i = 0; i < 26; i++)

            strings[i] = $"\"{(char)('a' + i)}\"";

        Console.WriteLine($"「{string.Join(",", strings)}」");

    }

}