#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <queue>
#include <string>
#include <map>
#include <set>
#include <stack>
#include <tuple>
#include <deque>
#include <array>
#include <numeric>
#include <bitset>
#include <iomanip>
#include <cassert>
#include <chrono>
#include <random>
#include <limits>
#include <iterator>
#include <functional>
#include <sstream>
#include <fstream>
#include <complex>
#include <cstring>
#include <unordered_map>
using namespace std;

using ll = long long;
using P = pair<int, int>;
constexpr int INF = 1001001001;
constexpr int mod = 1000000007;
// constexpr int mod = 998244353;

template<class T>
inline bool chmax(T& x, T y){
    if(x < y){
        x = y;
        return true;
    }
    return false;
}
template<class T>
inline bool chmin(T& x, T y){
    if(x > y){
        x = y;
        return true;
    }
    return false;
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int N;
    cin >> N;
    vector<ll> integer_part(N), decimal_part(N);
    for(int i = 0; i < N; ++i){
        string s;
        cin >> s;
        int n = s.length();
        bool update = false;
        for(int j = 0; j < n; ++j){
            if(s[j] == '.'){
                integer_part[i] = stoll(s.substr(0, j));
                string t = s.substr(j + 1, n - (j + 1));
                while(t.length() < 10)  t += '0';
                decimal_part[i] = stoll(t);
                if(s[0] == '-') decimal_part[i] *= -1LL;
                update = true;
                break;
            }
        }
        if(!update) integer_part[i] = stoll(s);
    }
    
    ll integer_sum = accumulate(begin(integer_part), end(integer_part), 0LL);
    ll decimal_sum = accumulate(begin(decimal_part), end(decimal_part), 0LL);
    integer_sum += decimal_sum / 10000000000LL;
    decimal_sum %= 10000000000LL;
    
    if(integer_sum > 0LL && decimal_sum < 0LL){
        integer_sum -= 1LL;
        decimal_sum += 10000000000LL;
    }
    else if(integer_sum < 0LL && decimal_sum > 0LL){
        integer_sum += 1LL;
        decimal_sum -= 10000000000LL;
    }

    string ans = "";
    if(integer_sum == 0 && decimal_sum < 0) ans += "-0";
    else    ans += to_string(integer_sum);
    string s = to_string(abs(decimal_sum));
    while(s.length() < 10)  s += '0';
    ans += '.' + s;

    cout << ans << endl;

    return 0;
}