20231115 - 阶乘之和

include

using namespace std; int main() {

int n;
cin >> n;
int s = 1,sum=0,mod = 1000000;
for (int i = 1; i <= n; i++) {
 s = (s * i) % mod;
	sum = (sum + s) % mod;
}
cout << sum;
return 0;

}