#include<iostream>
#include<string>
#include<math.h>
#include<algorithm>
using namespace std;


int main(){
	string s;
	string si;
	string sd;
	string ss="";
	int n;
	int keta;
	int kuriagari;
	long long int in = 0;
	long long int de = 0;
	long long int toi = 0;
	long long int tod = 0;
	int index;
	cin >> n;
	for (int i = 0; i < n; i++){
		cin >> s;
		index = (int)s.find(".");
		if (index == -1){
			in = stoi(s);
			de = 0;
		}
		else{
			si = s.substr(0, index);
			sd = s.substr(index + 1, s.length() - index);
			for (int is = 10 - sd.length(); is>0; is--){
				sd += "0";
			}
			in = stoi(si);
			de = stoi(sd);
		}
		toi += in;
		tod += de;
	}
	if (tod > 0){
		keta = 10 - ((int)log10(tod) + 1);
	}
	else{
		keta = 9;
	}
	if (keta<0){
		kuriagari = tod / 10000000000;
		toi += kuriagari;
		tod -= kuriagari * 10000000000;
		if (tod > 0){
			keta = 10 - ((int)log10(tod) + 1);
		}
		else{
			keta = 9;
		}

	}
	//cout << keta << endl;
	while (keta > 0){
		ss += "0";
		keta--;
	}
	//cout << ss << endl;
	cout << toi << "." << ss << tod << endl;
	return 0;
}