using System; using System.Linq; using System.Numerics; public static class Factorial { public static void Main(string[] args) { int num = 100; Console.WriteLine(Enumerable.Range(1, num).Select(i => new BigInteger(i)).Aggregate((a, b) => a * b)); } } // 93326215443944152681699238856266700490715968264381621468592963895217599993229915608941463976156518286253697920827223758251185210916864000000000000000000000000