#include <iostream>
#include <iomanip>
#include <algorithm>
#include <vector>
#include <string>

using lint = long long;

constexpr lint D = 10000000000;

void solve() {
    int n;
    std::cin >> n;

    lint x = 0, f = 0;
    while (n--) {
        std::string s;
        std::cin >> s;
        if (!std::count(s.begin(), s.end(), '.')) s += ".0";

        bool neg = (s.front() == '-');
        if (neg) s.erase(s.begin());

        lint nx = 0;
        while (s.front() != '.') {
            nx = nx * 10 + s.front() - '0';
            s.erase(s.begin());
        }

        s.erase(s.begin());

        while (s.length() < 10) s.push_back('0');
        lint nf = std::stoll(s);

        x += nx * (neg ? -1 : 1);
        f += nf * (neg ? -1 : 1);
    }

    while (f < 0) {
        f += D;
        --x;
    }
    while (f >= D) {
        f -= D;
        ++x;
    }

    bool neg = (x < 0);
    if (neg && f > 0) {
        ++x;
        f = D - f;
    }

    std::cout << (x == 0 && neg ? "-" : "") << x << "."
              << std::setw(10) << std::setfill('0') << f
              << std::endl;
}

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

    solve();

    return 0;
}