typedef long long ll;
typedef long double ld;

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

#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
template<typename T>
using ordered_set = tree<T, null_type, std::less<T>, rb_tree_tag, tree_order_statistics_node_update>;
// std::cout << *s.find_by_order(1) << std::endl; // 2

vector<string> split(string str, char del) {
   int first = 0;
   int last = str.find_first_of(del);
   vector<string> result;
 
   while (first < str.size()) {
     result.push_back(str.substr(first, last - first));
     first = last + 1;
     last = str.find_first_of(del, first);
     if (last == string::npos) last = str.size();
   }
   return result;
 }

signed main(){
    // これがないと落ちることがある
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    ll n;
    cin >> n;
    ll sei = 0;
    ll sho = 0;
    for (ll i = 0; i < n; i++){
        string a;
        cin >> a;
        bool mi = false;
        if(a[0]=='-')mi=true;
        bool dot = false;
        for (auto e : a) {
            if(e=='.')dot=true;
        }
        auto res = split(a, '.');
        sei+=stoll(res[0]);
        
        if(dot){
            auto num = res[1].insert(res[1].length(),10-res[1].length(),'0');
            if(mi){
                sho-=stoll(num);
            }else{
                sho+=stoll(num);
            }
            if(sho<0){
                sei--;
                sho+=10000000000;
            }
            sei += sho/10000000000;
            sho %= 10000000000;
        }
    }
    if(sei<0){
        sei++;
        sho = 10000000000-sho;
    }
    cout << sei<<"."<<to_string(sho).insert(to_string(sho).size(), 10-to_string(sho).size(), '0') << endl;
    
}