import java.util.Scanner;
public class J
{
public static void main(String args[])
{
//注释:int n=6;首次编译给定n的值
Scanner s=new Scanner(System.in);
System.out.println("请输入阶乘的数目");
int n=s.nextInt();
long sum=1;
for(int i=1;i<=n;i++)
{
sum=sum*i;
}
System.out.println(+n+"!="+sum);
}
}