#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); i++)
using namespace std;

#include <boost/multiprecision/cpp_dec_float.hpp>
namespace mp = boost::multiprecision;
using ld = mp::cpp_dec_float_50;

int main(){
    cin.tie(0);
    ios::sync_with_stdio(0);
    
    int N; cin >> N;
    ld sum = 0;
    rep(i,N) {
        ld a; cin >> a;
        sum += a;
    }
    cout << fixed << setprecision(10) << sum << endl;
}