Problem4323--n!的和

4323: n!的和

Time Limit: 1 Sec  Memory Limit: 128 MB
Submit: 4  Solved: 3
[Status] [Submit] [Creator:]

Description

求1!+2!+3!+...+n!的和

Input

输入n
n<=20

Output

一个大整数,表示阶乘的和

Sample Input Copy

5

Sample Output Copy

153

Source/Category