#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <stack>
#include <queue>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <ctime>

using namespace std;

inline int toInt(string s) {int v; istringstream sin(s);sin>>v;return v;}
template<class T> inline string toString(T x) {ostringstream sout;sout<<x;return sout.str();}

typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef tuple<int, int, int> TIII;
typedef long long LL;
typedef unsigned long long ULL;

#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)

#define MP make_pair
#define MT make_tuple
#define SZ(a) int((a).size())
#define EACH(i,c) for(auto i: c)
#define SORT(c) sort((c).begin(),(c).end())

#define ALL(a)  (a).begin(),(a).end()
#define RALL(a) (a).rbegin(), (a).rend()

const double EPS = 1e-10;
const double PI  = acos(-1.0);

#define dump(x)  cerr << #x << " = " << (x) << endl;
#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;

int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);

	const LL E = 1e10;
	int N;
	cin >> N;
	LL ret1 = 0, ret2 = 0;
	REP(i, N){
		string tmp;
		cin >> tmp;
		if(tmp.find('.') == string::npos){
			ret1 += stol(tmp);
		}
		else{
			auto pos = tmp.find('.');
			ret1 += stol(tmp.substr(0,pos));
			if(tmp[0] == '-') ret2 -= stol(tmp.substr(pos + 1).append(10 - tmp.length() + pos + 1, '0'));
			else ret2 += stol(tmp.substr(pos + 1).append(10 - tmp.length() + pos + 1, '0'));
		}
		//cout << ret1 << " " << ret2 << endl;
		if(ret1 < 0 && ret2 > 0){
			ret1++;
			ret2 -= E;
		}
		else if(ret1 > 0 && ret2 < 0){
			ret1--;
			ret2 += E;
		}
		ret1 += ret2 / E;
		ret2 %= E;
	}

	if(ret2 < 0) ret2 *= -1;
	string ret = toString(ret1) + ".";
	ret.append(10 - toString(ret2).length(), '0');
	ret += toString(ret2);

	cout << ret << endl;

	return 0;
}