CPZT ACGO

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#include <iostream>
#include <cmath>
using namespace std;
int pz[10005];
int cnt = 0;
void ch(int n) {
    for (int i = 1;i <= n;i++) {
        int sum = 1;
        for (int j = 1;j <= i;j++) {
            sum *= j;
        }
        cnt += sum;
    }
    cout << cnt;
} 
int main() {
	int n;
	cin >> n;
	ch(n);
	return 0;
}