#include <iostream>
#include <iomanip>
using namespace std;

int main() {
	int N;
	cin >> N;
	double ans = 0.0;
	for (int i = 0; i < N; i++) {
		double A;
		cin >> A;
		ans += A;
	}
	cout << fixed << setprecision(10) << ans << endl;
	return 0;
}