#include <bits/stdc++.h>
#define For(i, a, b) for(long long i = a; i < b; i++)
#define rep(i, n) For(i, 0, n)
#define rFor(i, a, b) for(long long i = a; i >= b; i--)
#define ALL(v) (v).begin(), (v).end()
#define rALL(v) (v).rbegin(), (v).rend()
using namespace std;

using lint = long long;
using ld = long double;

struct bint {
    vector<int> num;
    bool plus;
    
    bint() {}
    bint(string s, bool plus_) : num(s.size()), plus(plus_) {
        for (int i = 0; i < (int)s.size(); i++) {
            num[i] = s[(int)s.size() - i - 1] - '0';
        }
    }
};

vector<int> carry_and_fix(vector<int> a) {
    int n = a.size();
    for (int i = 0; i < n - 1; i++) {
        if (a[i] >= 10) {
            int k = a[i] / 10;
            a[i] -= k * 10;
            a[i + 1] += k;
        }
        if (a[i] < 0) {
            int k = (-a[i] - 1) / 10 + 1;
            a[i] += k * 10;
            a[i + 1] -= k;
        }
    }
    while (a.back() >= 10) {
        int k = a.back() / 10;
        a.back() -= k * 10;
        a.emplace_back(k);
    }
    while (a.size() >= 2 && a.back() == 0) {
        a.pop_back();
    }
    return a;
}

vector<int> addition(vector<int> a, vector<int> b) {
    int sa = a.size(), sb = b.size();
    int n = max(sa, sb);
    vector<int> res(n);
    for (int i = 0; i < n; i++) {
        res[i] = (i < sa ? a[i] : 0) + (i < sb ? b[i] : 0);
    }
    return carry_and_fix(res);
}

vector<int> subtraction(vector<int> a, vector<int> b) {
    int sa = a.size(), sb = b.size();
    int n = max(sa, sb);
    vector<int> res(n);
    for (int i = 0; i < n; i++) {
        res[i] = (i < sa ? a[i] : 0) - (i < sb ? b[i] : 0);
    }
    return carry_and_fix(res);
}

bool large_or_equal(vector<int> a, vector<int> b) {
    int sa = a.size(), sb = b.size();
    if (sa != sb) {
        return (sa > sb ? true : false);
    }
    for (int i = sa - 1; i >= 0; i--) {
        if (a[i] != b[i]) {
            return (a[i] > b[i] ? true : false);
        }
    }
    return true;
}

bint operator+(bint a, bint b) {
    bint res;
    if (a.plus && b.plus) {
        res.num = addition(a.num, b.num);
        res.plus = true;
    } else if (a.plus && !b.plus) {
        if (large_or_equal(a.num, b.num)) {
            res.num = subtraction(a.num, b.num);
            res.plus = true;
        } else {
            res.num = subtraction(b.num, a.num);
            res.plus = false;
        }
    } else if (!a.plus && b.plus) {
        if (large_or_equal(a.num, b.num)) {
            res.num = subtraction(a.num, b.num);
            res.plus = false;
        } else {
            res.num = subtraction(b.num, a.num);
            res.plus = true;
        }
    } else {
        res.num = addition(a.num, b.num);
        res.plus = false;
    }
    return res;
}

int main() {
    int n;
    cin >> n;
    auto conv = [](string s) {
        if (s[0] == '-') {
            s.erase(0, 1);
        }
        int n = s.size();
        int id = -1;
        rep(i, n) {
            if (s[i] == '.') {
                id = i;
            }
        }
        string res = "";
        if (id == -1) {
            res = s;
            rep(i, 10) {
                res += "0";
            }
        } else {
            res = s.substr(0, id);
            res += s.substr(id + 1);
            rep(i, 10 - (n - id - 1)) {
                res += "0";
            }
        }
        while (res.size() >= 2 && res[0] == '0') {
            res.erase(0, 1);
        }
        return res;
    };
    auto show = [](bint x) {
        vector<int> v = x.num;
        int n = v.size();
        string res = "";
        for (int i = 0; i < 10; i++) {
            res += v[i] + '0';
        }
        res += ".";
        for (int i = 10; i < n; i++) {
            res += v[i] + '0';
        }
        if (n == 10) {
            res += "0";
        }
        if (!x.plus) {
            res += "-";
        }
        reverse(res.begin(), res.end());
        return res;
    };
    bint ans("0", true);
    while (n--) {
        string s;
        cin >> s;
        bint x(conv(s), (s[0] != '-'));
        ans = ans + x;
    }
    cout << show(ans) << endl;
}