#include <iostream>
#include <iomanip>
#include <string>
#include <sstream>

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(0);
    
    int n;
    std::string input, inputInt, inputDec;
    long long int ansInt = 0, ansDec = 0;
    std::cin >> n;
    for(int i=0; i<n; ++i){
        std::cin >> input;
        if(input.find('.') == std::string::npos){
            ansInt += std::stoi(input);
        }else{
            std::istringstream ist(input);
            std::getline(ist, inputInt, '.');
            ansInt += std::stoi(inputInt);
            std::getline(ist, inputDec);
            while(inputDec.size()<10){
                inputDec += '0';
            }
            ansDec += static_cast<long long int>(std::stod(inputDec)) * ((input[0]=='-') ? -1 : 1);
        }
    }
    ansInt += ansDec/10000000000;
    ansDec %= 10000000000;
    inputDec = std::to_string(ansDec);
    while(inputDec.size()<10){
        inputDec += '0';
    }
    std::cout << ansInt << '.' << inputDec << "\n";

    return 0;
}