using System; using System.Linq; public class Program { public static void Main(string[] args) { var x = int.Parse(Console.ReadLine()); var ans = Draw(x); Console.WriteLine(ans); } public static string Draw(int x) { if (x % 2 == 0) { return "invalid"; } var mid = x / 2; var matrix = Enumerable.Range(0, x).Select((i) => Enumerable.Repeat(".", x).ToList()).ToList(); foreach (var i in Enumerable.Rang