#include <bits/stdc++.h>
using namespace std;

#include <boost/multiprecision/cpp_int.hpp>
#include <boost/multiprecision/cpp_dec_float.hpp>
using namespace boost::multiprecision;

using bint = cpp_int;
// using bdec = cpp_dec_float_100;
using bdec = number<cpp_dec_float<10000>>;

template <typename T, typename U> void cmin(T &a, U b) {
  if (a > b) a = b;
}
template <typename T, typename U> void cmax(T &a, U b) {
  if (a < b) a = b;
}

signed main() {
  cin.tie(nullptr);
  ios_base::sync_with_stdio(false);

  int N;
  cin >> N;
  bdec ans = 0;
  bdec in;
  while (cin >> in) ans += in;
  cout << fixed << setprecision(10) << ans << "\n";
}