Work3

//求1+2!+3!+...+20!的和

 public  class Work3{
  public static void main(String args[]){
  int i=1,s=0,sum=1;
  while(i<=20){
  sum*=i;
  i++;
  s+=sum;
 }
  System.out.printf("%d\n",s);
 }
}