#include <algorithm>
#include <cstdio>
#include <bitset>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <string>
#include <utility>
#include <vector>

#define REP(i,s,n) for(int i=(int)(s);i<(int)(n);i++)

using namespace std;
typedef long long int ll;
typedef vector<int> VI;
typedef pair<int, int> PI;
const double EPS=1e-9;
#define  FF long double


int main(void) {
  FF s = 0;
  int n;
  cin >> n;
  REP(i, 0, n) {
    FF q;
    cin >> q;
    s += q;
  }
  printf("%.10Lf\n", s);
  
}