using System.Linq; using System.Collections.Generic; using System; public static class Permi { public static IEnumerable> Perm(this IEnumerable items, int? k = null) { if (k == null) k = items.Count(); if (k == 0) yield return Enumerable.Empty(); else { var i = 0; foreach (var x in items) { var xs = items.Where((_, index) => i != index); foreach (var c in Perm(xs, k - 1)) yield return c.Before(x); i++; } } } public static IEnumerable Before(this IEnumerable items, T first) { yield return first; foreach (var i in items) yield return i; } } public class Hello { static void Main() { var k = int.Parse(Console.ReadLine().Trim()); var count = 0; var a = "12345678".ToCharArray().Perm(); foreach (var x in a) { var b = int.Parse(string.Join("", x)); if (b % k == 0) count++; } Console.WriteLine(count); } }