#include <iostream>
#include <string>
#define ll long long
using namespace std;

int main(){
    int N;
    cin >> N;
    ll sum_ll = 0;
    ll sum_double = 0;
    string a;

    for (int i = 0; i < N; i++) {
        cin >> a;
        int minus = a.find("-");
        if (minus == string::npos){
            int comma = a.find(".");
            if (comma == string::npos) {
                sum_ll += stoll(a);
            } else {
                sum_ll += stoll(a.substr(0, comma));
                string a_double = a.substr(comma + 1);
                for (int j = a_double.length(); j < 10; j++) {
                    a_double += "0";
                }
                sum_double += stoll(a_double);
            }
        } else {
            a = a.substr(1);
            int comma = a.find(".");
            if (comma == string::npos) {
                sum_ll -= stoll(a);
            } else {
                sum_ll -= stoll(a.substr(0, comma));
                string a_double = a.substr(comma + 1);
                for (int j = a_double.length(); j < 10; j++) {
                    a_double += "0";
                }
                sum_double -= stoll(a_double);
            }
        }
    }

    // 小数点部分の合計を整数部分と少数部分に分離
    string sum_double_str = to_string(sum_double);
    int minus = sum_double_str.find("-");
    if (minus != string::npos){
        int sum_double_str_len = sum_double_str.length();
        if (sum_double_str_len > 10){
            ll sum_double_ll = stoll(sum_double_str.substr(0, sum_double_str_len - 10));
            sum_ll += sum_double_ll;
            sum_double_str = sum_double_str.substr(sum_double_str_len - 10);
        } else {
            for (int j = sum_double_str.length(); j < 10; j++) {
                sum_double_str += "0";
            }
        }
    } else {
        sum_double_str = sum_double_str.substr(1);
        int sum_double_str_len = sum_double_str.length();
        if (sum_double_str_len > 10){
            ll sum_double_ll = stoll(sum_double_str.substr(0, sum_double_str_len - 10));
            sum_ll -= 1;
            sum_ll -= sum_double_ll;
            sum_double = stoll(sum_double_str.substr(sum_double_str_len - 10));
            sum_double = 10000000000 - sum_double;
        } else {
            sum_ll -= 1;
            for (int j = sum_double_str.length(); j < 10; j++) {
                sum_double_str += "0";
            }
            sum_double = 10000000000 - sum_double;
        }
    }
    
    cout << sum_ll << "." << sum_double_str;

    return 0;
}