using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
Jiecheng namespace
{
class Jiecheng
{
public int Jc (int num)
{
return num > 0 ? num *Jc(num - 1):1; //如果num>0则返回num *Jc(num - 1),否则返回1
}
}
class excutejiecheng
{
static void Main(string[] args)
{
jiecheng n = new jiecheng();
int result = n.Jc(Convert.ToInt16(Console.ReadLine()));
Console.WriteLine("result is {0}",result);
Console.ReadKey();
}
}
}