#include <bits/stdc++.h>

using namespace std;

int N;
string over("0000000000"), under("0000000000");
int dot = 0;
bool flag = false;

int main(void){
    
    cin >> N;
    
    int i;
    
    for(i = 0; i < N; ++i){
        string s;
        cin >> s;
        
        if(s.find(".") == string::npos){ //小数点以下なし
            
            over = to_string(stoll(s) + stoll(over));
            
        }
        else{   //小数点以下あり
            string aaaa, bbbb;
            aaaa = s.substr(0, s.find("."));
            bbbb = s.substr(s.find(".") + 1);
            
            over = to_string(stoll(aaaa) + stoll(over));
            
            while(bbbb.size() != 10) bbbb += '0';
            under = to_string( ((s[0] == '-') ? stoll(bbbb) * (-1) : stoll(bbbb)) + ((flag) ? stoll(under) * (-1) : stoll(under)) );
            
            if(under[0] == '-'){
                flag = true;
                under.erase(under.begin());
            }
            else flag = false;
            if(under.size() >= 10) dot = under.size() - 10;
            while(under.size() < 10) under = '0' + under;
            
        }
    }
    
    if(dot != 0){ //繰り上がりあり
        string plus;
        plus = under.substr(0, dot);
        under = under.substr(dot);
        over = to_string(stoll(over) + ((flag) ? stoll(plus) * (-1) : stoll(plus)) );
    }
    
    if(stoll(over) != 0 && stoll(under) != 0 && ((over[0] == '-' && !flag) || (over[0] != '-' && flag))){ //整数部分と小数部分の符号が不一致 
        over = (stoll(over) > 0) ? to_string(stoll(over) - 1) : to_string(stoll(over) + 1);
        under = to_string(10000000000 - stoll(under));
        flag = (flag) ? false : true;
        while(under.size() < 10) under = '0' + under;
    }
    
    if(over[0] == '0' && flag) cout << "-" << over << "." << under << endl;
    else cout << over << "." << under << endl;
    
    return 0;
    
}