#include <iostream>
#include <boost/multiprecision/cpp_dec_float.hpp>
using namespace std;
using ld = boost::multiprecision::cpp_dec_float_100;
int main()
{
    int N;
    cin >> N;
    ld sum = 0;
    for (int i = 0; i < N; i++) {
        ld a;
        cin >> a;
        sum += a;
    }
    cout << fixed << setprecision(10) << sum << endl;
    return 0;
}