#include <iostream>
#include <vector>
#include <algorithm>
#include <iomanip>
using namespace std;

#define RREP(i,s,e) for (i = e-1; i >= s; i--)
#define rrep(i,n) RREP(i,0,n)
#define REP(i,s,e) for (i = s; i < e; i++)
#define rep(i,n) REP(i,0,n)
#define INF 1e8

typedef long long ll;

int main() {
    int i, n;
    ll ua, la;
    cin >> n;
    ua = la = 0;
    rep (i,n) {
        string s;
        ll u, l = 0;
        size_t len;
        cin >> s;
        u = stoll(s,&len);
        if (len < s.size()) {
            string t;
            t = s.substr(len+1);
            while (t.size() < 10)
                t.push_back('0');
            l = stoll(t);
        }
        ua += u;
        if (stod(s) >= 0 && ua >= 0 || stod(s) < 0 && ua < 0)
            la += l;
        else
            la -= l;
        if (la < 0) {
            la += 10000000000;
            ua--;
        }
    }
    cout << ua + la / 10000000000 << '.' << setw(10) << setfill('0') << la % 10000000000 << endl;
    return 0;
}