import java.util.*;
public class Test
{
	public static void main(String[] args)
	{
		System.out.println("请输入一个数：");
		Scanner sc = new Scanner(System.in);
		int num = sc.nextInt();
		int result = 1;
		for(int i = 1;i<=num;i++)
		{
			result *= i;
		}
		System.out.println(num+"这个数的阶乘为："+result);
	}
}