/*************************************************************************
 *  Compilation:  javac NoBaseCase.java
 *  Execution:    java NoBaseCase N
 *  
 *  A recursive function without a base case.
 *
 *  % java NoBaseCase 5
 *  Exception in thread "main" java.lang.StackOverflowError
 *  at NoBaseCase.factorial(NoBaseCase.java:20)
 *  at NoBaseCase.factorial(NoBaseCase.java:20)
 *  at NoBaseCase.factorial(NoBaseCase.java:20)
 *
 *************************************************************************/

public class NoBaseCase {
    public static int factorial(int n) {
        return n * factorial(n-1);
    }

    public static void main(String[] args) {
        int N = Integer.parseInt(args[0]);
        System.out.println(factorial(N));
    }

}