#line 2 "/home/sakflat/CP/_library/cpp/template/template.cpp"

//yukicoder@cpp17

#include <iostream>

#include <cmath>
#include <algorithm>

#include <iomanip>

#include <string>
#include <vector>
#include <set>
#include <stack>
#include <queue>
#include <map>

#include <bitset>

#include <complex>

#include <cctype>
#include <utility>
#include <climits>

#include <numeric>

using namespace std;
using ll = long long;
using P = pair<ll,ll>;

const ll MOD = 998244353;
const ll MODx = 1000000007;
const int INF = (1<<30)-1;
const ll LINF = (1LL<<62LL)-1;
const double EPS = (1e-10);

P ar4[4] = {{0,1},{0,-1},{1,0},{-1,0}};
P ar8[8] = {{-1,-1},{-1,0},{-1,1},{0,-1},{0,1},{1,-1},{1,0},{1,1}};




template <typename T> vector<T> make_vector(size_t a, T b) { return vector<T>(a, b); }
template <typename... Ts> auto make_vector(size_t a, Ts... ts) { return vector<decltype(make_vector(ts...))>(a, make_vector(ts...)); }
 
 /*
確認ポイント
cout << fixed << setprecision(n) << 小数計算//n桁の小数表記になる

計算量は変わらないが楽できるシリーズ
min(max)_element(iter,iter)で一番小さい(大きい)値のポインタが帰ってくる
count(iter,iter,int)でintがiterからiterの間にいくつあったかを取得できる
*/

/*
function corner below
*/


/*
Function corner above
*/

/* comment outed because can cause bugs
__attribute__((constructor))
void initial() {
 cin.tie(0);
 ios::sync_with_stdio(false);
}
*/
#line 2 "/home/sakflat/CP/_library/cpp/template/basic.cpp"

int digit[20];

int main(){
  int n;cin>>n;
  long long sei = 0;
  long long shou = 0;
  for(int i = 0; n > i; i++){
    string s;cin>>s;
    int div = -1;
    for(int j = 0; s.size() > j; j++){
      if(s[j] == '.'){
        div = j;
      }
    }
    if(div == -1){
      if(sei >= 0 && sei + stoll(s) < 0 && shou){
        shou = 10000000000 - shou;
        sei += stoll(s)+1;
      }
    }else{
      bool rev = s[0] == '-';
      string tmpsei = s.substr(0, div);
      string tmpshou = s.substr(div+1, s.size()-div);
      while(tmpshou.size() != 10){
        tmpshou.push_back('0');
      }
      if(sei >= 0 && sei+stoll(tmpsei) < 0 && shou){
        sei += 1;
        shou = -(10000000000 - (shou - stoll(tmpshou)));
      }else{
        shou += stoll(tmpshou) * (rev ? -1 : 1);
      }
      sei += stoll(tmpsei);
    }
  }
  if(shou < 0){
    int kari = (shou / 10000000000LL) * -1 + 1;
    if(sei >= kari){
      sei -= kari;
      shou = ((shou % 10000000000LL) + 10000000000LL) % 10000000000LL;
    }else{
      sei -= (kari-1);
      shou = -1*shou % 10000000000LL;
      if(sei == 0)cout << "-";
    }
  }else{
    sei += shou / 10000000000LL;
    shou = shou % 10000000000LL;

  }
  string formatshou = to_string(shou);
  while(formatshou.size() != 10){
    formatshou = "0" + formatshou;
  }
  cout << sei << "." << formatshou << endl;
  
  return 0;
}