#include <bits/stdc++.h>

using namespace std;

#define REP(i,a,b) for(int i=a;i<(long long)b;i++)
#define rep(i,n) REP(i,0,n)

typedef long long ull;

int main() {
  
  int N; cin >> N;
  
  ull sum = 0;
  rep(i, N) {
    long double d; cin >> d;
    sum += d*(1e10);
  }
  
  string s; stringstream ss; ss << sum;
  ss >> s; int sz = s.size();
  rep(i, sz-10) {
    cout << s[i];
  }
  cout << ".";
  REP(i, sz-10, sz) {
    cout << s[i];
  }
  cout << endl;
  
  return 0;
}