//CFAN 2002
//遞歸算法
//求階乘
import java.io.*;
public class DiGui
{
public static void main(String args[])
{
int i=0;
char ch=' ';
String s;
Child ren=new Child();
try
{
System.out.println("Please intput a Number,End whit '#'");
do
{
BufferedReader br=new BufferedReader(new InputStreamReaderSystem.in));
s =br.readLine();
i=Integer.parseInt(s);
System.out.println(ren.Factorial(i));
}
while(ch!='#');
}catch(IOException e){}
}
}
class Child
{
double Factorial(int n)
{
if (n==1)
return 1;
else
return n*Factorial(n-1);
}
}