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

#define REP(i, a, b) for (int i = int(a); i < int(b); i++)
#ifdef _DEBUG_
#define dump(val) cerr << __LINE__ << ":\t" << #val << " = " << (val) << endl
#else
#define dump(val)
#endif

using namespace std;

typedef long long int ll;

template<typename T>
vector<T> make_v(size_t a, T b) {
    return vector<T>(a, b);
}

template<typename... Ts>
auto make_v(size_t a, Ts... ts) {
    return vector<decltype(make_v(ts...))>(a, make_v(ts...));
}

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int n;
    cin >> n;
    ll a = 0, b = 0;
    REP(i, 0, n) {
        string s;
        cin >> s;
        int sign = 1;
        if (s[0] == '-') {
            s = s.substr(1);
            sign = -1;
        }
        auto it = s.find('.');
        if (it != string::npos) {
            REP(j, s.size() - it, 11) {
                s += "0";
            }
        } else {
            s += ".0000000000";
        }
        it = s.find('.');
        a += sign * atoll(s.substr(0, it).c_str());
        b += sign * atoll(s.substr(it + 1).c_str());

        if (a < 0 && b > 0) {
            a++;
            b = b - 10000000000;
        } else if (a > 0 && b < 0) {
            a--;
            b = 10000000000 + b;
        }
        if (b >= 10000000000) {
            b -= 10000000000;
            a++;
        }
        if (b <= -10000000000) {
            b += 10000000000;
            a--;
        }
    }
    if (b < 0) {
        b *= -1;
        if (a == 0) {
            cout << '-';
        }
    }
    cout << a << "." << setw(10) << setfill('0') << b << endl;
    return 0;
}