import java.io.*;
import java.math.BigInteger;
import java.util.*;
public class Main {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
         Scanner cin=new Scanner (new BufferedInputStream(System.in));
            PrintWriter cout=new PrintWriter(System.out);
            int t;
            //t=cin.nextInt();
            //int eg=1;
            while(cin.hasNextInt())
            {
                t=cin.nextInt();
                BigInteger one=new BigInteger("1");
                BigInteger ans=one;
                BigInteger tmp =one;
                for(int i=0;i<t;i++){

                    ans=ans.multiply(tmp);
                    tmp=tmp.add(one);
                }
                //System.out.println(ans);
                System.out.println(ans);


            }
    }


}