23 lines
361 B
C++
23 lines
361 B
C++
|
#include <bits/stdc++.h>
|
||
|
|
|
||
|
|
using namespace std;
|
||
|
|
|
||
|
|
int jiecheng(int n) {
|
||
|
|
int result = 1;
|
||
|
|
for (int i = 1; i <= n; ++i) {
|
||
|
|
result *= i;
|
||
|
|
}
|
||
|
|
return result;
|
||
|
|
}
|
||
|
|
|
||
|
|
int main() {
|
||
|
|
int n;
|
||
|
|
cin >> n;
|
||
|
|
int sum = 0;
|
||
|
|
for (int i = 1; i <= n; ++i) {
|
||
|
|
sum += jiecheng(i);
|
||
|
|
}
|
||
|
|
cout << sum << endl;
|
||
|
|
return 0;
|
||
|
|
}
|