import java.util.*;
import java.lang.*;
import java.io.*;

// The main method must be in a class named "Main".
class Main {
    static int factorial(int n)
    {
        if(n==0||n==1) return 1;
        return factorial(n-1)*n;
    }
    public static void main(String[] args) {
        System.out.println(factorial(5));
        /*int f=1;
        for(int i=1;i<=5;i++)
        {
            f=f*i;
        }
        System.out.println(f);*/
    }
}