#pragma GCC target("avx2")
#pragma GCC optimize("03")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
using namespace std; typedef long double ld; typedef long long ll;
typedef unsigned long long ull;
#define endl "\n"
#define FOR(i,a,b) for(int i=(a);i<=(b);i++)
#define rep(i,n) for(int i=0;i<(n);i++)
#define PII pair<int, int>
#define PLL pair<ll, ll>
#define ALL(x) (x).begin(), (x).end()
constexpr int INF=1<<30; constexpr ll LINF=1LL<<60; constexpr ll mod=1e9+7; constexpr int NIL = -1;
template<class T>vector<T> vec(int len, T elem) { return vector<T>(len, elem); } // auto dp = vec(52, vec(103, vec(103, INF)));
template<class T>inline bool chmax(T &a, const T &b) { if (a<b) { a = b; return 1; } return 0; }
template<class T>inline bool chmin(T &a, const T &b) { if (b<a) { a = b; return 1; } return 0; }
template<class T>inline int popcount(T a) {return __builtin_popcount(a);}
template<class T>inline T emod(T a, T p) { return (a%p + p) % p;}
template <typename T> istream &operator>>(istream &is, vector<T> &vec) { for (auto &v : vec) is >> v; return is; }
template <typename T> ostream &operator<<(ostream &os, const vector<T> &vec) {os << '\n'; for (auto v : vec) os << v << ' '; os << '\n'; return os;}
template <typename T> ostream &operator<<(ostream &os, const deque<T> &vec) { os << "deq["; for (auto v : vec) os << v << ','; os << ']'; return os; }
template <typename T> ostream &operator<<(ostream &os, const set<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <typename T> ostream &operator<<(ostream &os, const unordered_set<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <typename T> ostream &operator<<(ostream &os, const multiset<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <typename T> ostream &operator<<(ostream &os, const unordered_multiset<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <typename T1, typename T2> ostream &operator<<(ostream &os, const pair<T1, T2> &pa) { os << '(' << pa.first << ',' << pa.second << ')'; return os; }
template <typename TK, typename TV> ostream &operator<<(ostream &os, const map<TK, TV> &mp) { os << '{'; for (auto v : mp) os << v.first << "=>" << v.second << ','; os << '}'; return os; }
template <typename TK, typename TV> ostream &operator<<(ostream &os, const unordered_map<TK, TV> &mp) { os << '{'; for (auto v : mp) os << v.first << "=>" << v.second << ','; os << '}'; return os; }
//-------------------
int main() {
    cin.tie(0); ios::sync_with_stdio(false); cout << fixed << setprecision(10);
    int n; cin >> n;
    ll up = 0;
    ll down = 0;
    rep(i,n) {
        string a; cin >> a;
        int ten = a.size();
        rep(i, a.size()) {
            if(a[i]=='.') ten=i;
        }
        if(ten==a.size()) {
            if(a[0]=='-') {
                up -= stoll(a.substr(1, a.size()-1));
                // cout << up << endl;
            } else {
                up += stoll(a);
            }
        } else {
            if(a[0]=='-') {
                up -= stoll(a.substr(1,ten-1));
                int sz = a.size()-ten-1;
                ll minus = stoll(a.substr(ten+1, sz)+string(10-sz, '0'));
                if(down < minus) {
                    up--;
                    down = down + (ll) 1e10 - minus;
                } else {
                    down -= minus;
                }
            } else {
                up += stoll(a.substr(0,ten));
                int sz = a.size()-ten-1;
                ll minus = stoll(a.substr(ten+1, sz)+string(10-sz, '0'));
                if(down + minus >= 1e10) {
                    up++;
                    down = down + minus - 1e10;
                } else {
                    down += minus;
                }
            }
        } 
    }
    if(up<0 and down >0) {
        up++;
        down = (ll) 1e10 - down; 
    }
    if(up != 0) printf("%ld.", up);
    else printf("0.");
    printf("%010ld\n", down);
    return 0;
}