using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using System.Globalization;
using static System.Console;
using Pair = System.Collections.Generic.KeyValuePair<int, int>;

class Program
{
    static void Main()
    {
        var sw = new StreamWriter(OpenStandardOutput()) { AutoFlush = false };
        SetOut(sw);
        new Program().solve();
        Out.Flush();
    }
    Scanner cin = new Scanner();
    readonly int[] dd = { 0, 1, 0, -1, 0 };
    readonly int mod = 1000000007;
    readonly string alfa = "abcdefghijklmnopqrstuvwxyz";


    void solve()
    {
        int n = cin.nextint;
        long lsum = 0;
        long dsum = 0;

        for (int i = 0; i < n; i++)
        {
            string s = cin.next;

            int j = 0; bool flag = true;
            if(s[j] == '-')
            {
                j = 1;
                flag = false;
            }

            long l = 0;
            while (j < s.Length && s[j] != '.')
            {
                l *= 10;
                l += int.Parse(s[j].ToString());
                j++;
            }
            if (flag)
            {
                lsum += l;
            }
            else
            {
                lsum -= l;
            }

            long d = 0;
            for (int k = 1; k <= 10; k++)
            {
                d *= 10;
                if (j + k >= s.Length) continue;

                d += int.Parse(s[j + k].ToString());
            }
            if (flag)
            {
                dsum += d;
            }
            else
            {
                dsum -= d;
            }
        }

        lsum += dsum / (long)Math.Pow(10, 10);
      
        var mod = Math.Abs(dsum % (long)Math.Pow(10, 10));
       
        Write(lsum + ".");

        if (mod == 0)
        {
            WriteLine("0000000000");
        }
        else
        {
            WriteLine(mod);
        }
    }

}

class Scanner
{
    string[] s; int i;
    char[] cs = new char[] { ' ' };
    public Scanner() { s = new string[0]; i = 0; }
    public string[] scan { get { return ReadLine().Split(); } }
    public int[] scanint { get { return Array.ConvertAll(scan, int.Parse); } }
    public long[] scanlong { get { return Array.ConvertAll(scan, long.Parse); } }
    public double[] scandouble { get { return Array.ConvertAll(scan, double.Parse); } }
    public string next
    {
        get
        {
            if (i < s.Length) return s[i++];
            string st = ReadLine();
            while (st == "") st = ReadLine();
            s = st.Split(cs, StringSplitOptions.RemoveEmptyEntries);
            i = 0;
            return next;
        }
    }
    public int nextint { get { return int.Parse(next); } }
    public long nextlong { get { return long.Parse(next); } }
    public double nextdouble { get { return double.Parse(next); } }
}