#include "bits/stdc++.h"
using namespace std;

int main(){
	long long a = 0;
	long long b = 0;
	int N;
	cin >> N;
	for (int i = 0; i < N; i++)
	{
		string s;
		cin >> s;

		bool minus = 0;
		if (s[0] == '-'){
			minus = 1;
		}

		long long c = 0;
		long long adda = 0;
		long long addb = 0;
		double mul = 1;
		for (int j = s.size() - 1; j >= minus; j--)
		{
			if (s[j] == '.'){
				int need = 10 - (s.size() - j) + 1;
				for (int k = 0; k < need; k++)
				{
					c *= 10;
				}
				addb += c;
				c = 0;
				mul = 1;
			}
			else{
				c += (s[j] - '0') * mul;
				mul *= 10;
			}
		}
		adda += c;
		if (minus){
			a -= adda;
			b -= addb;
		}
		else{
			a += adda;
			b += addb;
		}
	}
	long long mod = (long long)1e10;
	a += b / mod;
	b %= mod;

	if (a == 0 && b < 0){
		cout << "-";
		b *= -1;
	}

	if (a < 0){
		if (b <= 0){
			b *= -1;
		}
		else{
			a++;
			b -= mod;
			b *= -1;
			if (a == 0) cout << "-";
		}
	}
	else{
		if (b < 0){
			a--;
			b += mod;
		}
	}
	printf("%lld", a);
	printf(".");
	printf("%010lld\n", b);
	cin >> a;
}