L1-013 计算阶乘和 (10 分)
import java.util.Scanner;
/**
*
* @author 曹家伟
*
*/
public class Main {
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner s=new Scanner(System.in);
int n=s.nextInt();
int sum=0;
for(int i=1;i<=n;i++) {
int p=1;
for(int j=1;j<=i;j++) {
p=p*j;
}
sum=sum+p;
}
System.out.print(sum);
}
}