#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <climits>
#include <cmath>
#include <string>
#include <vector>
#include <algorithm>
#include <queue>
#include <map>
#include <functional>
#include <set>
#include <numeric>
#include <stack>
#include <utility>
#include <time.h>
#include <iterator>
//#include "util.h"

using namespace std;
typedef unsigned uint;
typedef long long lint;
typedef unsigned long long ulint;



//呪文
template <typename _KTy, typename _Ty> ostream& operator << (ostream& ostr, const pair<_KTy, _Ty>& m) { cout << "{" << m.first << ", " << m.second << "}"; return ostr; }
template <typename _KTy, typename _Ty> ostream& operator << (ostream& ostr, const map<_KTy, _Ty>& m) { if (m.empty()) { cout << "{ }"; return ostr; } cout << "{" << *m.begin(); for (auto itr = ++m.begin(); itr != m.end(); itr++) { cout << ", " << *itr; } cout << "}"; return ostr; }
template <typename _Ty> ostream& operator << (ostream& ostr, const vector<_Ty>& v) { if (v.empty()) { cout << "{ }"; return ostr; }	cout << "{" << v.front(); for (auto itr = ++v.begin(); itr != v.end(); itr++) { cout << ", " << *itr; }	cout << "}"; return ostr; }
template <typename _Ty> ostream& operator << (ostream& ostr, const set<_Ty>& s) { if (s.empty()) { cout << "{ }"; return ostr; } cout << "{" << *(s.begin()); for (auto itr = ++s.begin(); itr != s.end(); itr++) { cout << ", " << *itr; }	cout << "}"; return ostr; }
//template <typename T> void print(T* v, int N) { if (N == 0) cout << "{ }"; cout << "{" << v[0]; for (int i = 1; i < N; i++) cout << ", " << v[i]; cout << "}"; }
#define PI 3.14159265358979323846
#define EPS 1e-12
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)
#define all(x) (x).begin(), (x).end()



// 小数点以下を整数に変換
lint convert(string B)
{
	// 末尾に 0 を加えて 10 桁に
	B += string(10 - B.size(), '0');

	// 先頭の 0 を取り除く
	while (B[0] == '0' && B.size() > 1) B = B.substr(1);

	return stoll(B);
}

// 逆変換
string convert(lint n)
{
	string B = to_string(n);
	B = string(10 - B.size(), '0') + B;
	return B;
}

int yuki0081()
{
	const lint E = 10000000000;

	int N;
	cin >> N;

	lint a = 0; // 整数部
	lint b = 0; // 小数部

	string A;
	REP(i, N) {
		cin >> A;

		bool minus = (A[0] == '-');
		string::size_type index = A.find('.');

		// 整数
		if (index == string::npos)
			a += stoll(A);
		// 小数
		else {
			a += stoll(A.substr(0, index));
			b += (minus ? -convert(A.substr(index + 1)) : convert(A.substr(index + 1)));
		}
	}

	if (b >= 0) {
		a += b / E;
		b %= E;
	}
	else {
		a += b / E - 1;
		b = E + b % E;
	}

	if (a >= 0 || b == 0)
		cout << to_string(a) + '.' + convert(b) << endl;
	else {
		a++;
		b = E - b;

		cout << (a == 0 ? "-" : "") + to_string(a) + '.' + convert(b) << endl;
	}

	return 0;
}

int main()
{
	//clock_t start, end;
	//start = clock();

	yuki0081();

	//end = clock();
	//printf("%d msec.\n", end - start);

	return 0;
}