#include<stdio.h>
int main()
{
long long int x
,y
,total
,demaxiya
;
scanf("%lld",&y
);
demaxiya
=1;
while(y
>1){
total
=1;
for(x
=y
;x
>1;x
--){
total
*=x
;
}
y
--;
demaxiya
+=total
;
}
printf("%lld",demaxiya
);
}
转载请注明原文地址: https://lol.8miu.com/read-34212.html