import java.util.Scanner;
public class FactorialSum
{
public static int factorial(int n)
{
int result=1;
for(int i=1;i<=n;i++)
{
result=result*i;
}
return result;
}
public static void main(String[] args)
{
int sum=0,number;
Scanner scanner=new Scanner(System.in);
System.out.print("请输入一个正整数:");
number=scanner.nextInt();
for( int i=1;i<=number;i++)
{
sum=sum+factorial(i);
}
System.out.println("从1到"+number+"的阶乘和为:"+sum);
}
}



