import java.math.BigInteger;
import java.util.Scanner;

public class Factorial_6_Scanner {
   public static final int MAX = 25; 
   
   public static BigInteger factorial(int n) {
     BigInteger prod = BigInteger.ONE;
     for (int i=1; i<=n; i++)
       prod = prod.multiply(new BigInteger(i +""));
     return prod;
   }
  
  public static void main(String[] args) {
     Scanner sc = new Scanner(System.in);
     System.out.print("Enter a nonnegative integer: ");
     int n = sc.nextInt();
     System.out.println(n + "! = " + factorial(n) );
  }
}