import java.io.*;

class Factorial1
{
// Prompts for a number and prints its factorial
// (recursive version)

 public static void main(String[] args) throws IOException
 {
  String num;
  int n;
  BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
  System.out.print("Type the number: ");
  num=in.readLine();
  for(;;) try
     {
      n=Integer.parseInt(num);
      break;
     }
  catch(NumberFormatException e)
     {
      System.out.println("Not an integer, try again: ");
     }
  System.out.println(n+"! is: "+factorial(n));
 }

 public static int factorial(int n)
 {
  if(n<=1) 
     return 1;
  else
     return n*factorial(n-1);
 }

}