#include <iostream>
using namespace std;
using ll = long long;
constexpr ll OFFSET = 1e10;
int main()
{
    int N;
    cin >> N;
    ll sum = 0;
    for (int n = 0; n < N; n++) {
        string s;
        cin >> s;
        string st[2];
        int ind = 0;
        for (int i = 0; i < s.size(); i++) {
            if (s[i] == '-') {
                st[0].push_back('-');
                st[1].push_back('-');
                continue;
            }
            if (s[i] == '.') {
                ind = 1;
                continue;
            }
            st[ind].push_back(s[i]);
        }
        ll integer = 0;
        ll floating = 0;
        integer = stoll(st[0]);
        if (not st[1].empty()) {
            const int size = (st[1][0] == '-') ? st[1].size() - 1 : st[1].size();
            for (int i = 0; i < 10 - size; i++) {
                st[1].push_back('0');
            }
            string ss;
            bool start = false;
            for (int i = 0; i < st[1].size(); i++) {
                if (st[1][i] == '0' and (not start)) {
                    continue;
                }
                start = true;
                ss.push_back(st[1][i]);
            }
            floating = stoll(ss);
        } else {
            floating = 0;
        }
        sum += integer * OFFSET + floating;
    }
    const ll integer = sum / OFFSET;
    cout << integer << ".";
    const ll floating = sum % OFFSET;
    ll num = floating;
    char s[10];
    for (int i = 0; i < 10; i++) {
        s[9 - i] = '0' + num % 10;
        num /= 10;
    }
    for (int i = 0; i < 10; i++) {
        cout << s[i];
    }
    cout << endl;

    return 0;
}