import java.util.*;

class Main{
    public static void main(String args[]){
    Scanner cin = new Scanner(System.in);

    long target = cin.nextLong();
    long res = func(target);
    
    int size = String.valueOf(res).length();

    if(size>12){
    res = (long)(res/Math.pow(10,size-1));
    }
    System.out.println(res);
    }

    static long func(long num){
        if(num==0){
            return 1;
        }
    return num*func(num-1);
    }
}