#include<iostream>
#include<algorithm>
#include<cstdio>
#include<cmath>
#include<cctype>
#include<math.h>
#include<string>
#include<string.h>
#include<stack>
#include<queue>
#include<vector>
#include<utility>
#include<set>
#include<map>
#include<stdlib.h>
#include<iomanip>

using namespace std;

#define ll long long
#define ld long double
#define EPS 0.0000000001
#define INF 1e9
#define LINF (ll)INF*INF
#define MOD 1000000007
#define rep(i,n) for(int i=0;i<(n);i++)
#define loop(i,a,n) for(int i=a;i<(n);i++)
#define all(in) in.begin(),in.end()
#define shosu(x) fixed<<setprecision(x)

#define int ll //!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

typedef vector<int> vi;
typedef vector<string> vs;
typedef pair<int,int> pii;
typedef vector<pii> vp;

int gcd(int a, int b){
    if(b==0) return a;
    return gcd(b,a%b);
}
int lcm(int a, int b){
    return a*b/gcd(a,b);
}

#define geta 10000000000LL

pii f(string s){
    int ret1 = 0, ret2 = 0;
    int i = 0;
    while(i < s.size() && s[i] != '.'){
        ret1 *= 10;
        ret1 += s[i]-'0';
        i++;
    }
    if(i < s.size()){
        i++;
        rep(j,10){
            ret2 *= 10;
            if(i+j < s.size())ret2 += s[i+j]-'0';
        }
    }
    //cout << ret1 << " " << ret2 << endl;
    return pii(ret1,ret2);
}

signed main(void) {
    int n;
    cin >> n;
    int ans1 = 0, ans2 = 0;
    rep(i,n){
        string s;
        cin >> s;
        pii t;
        if(s[0] == '-'){
            t = f(s.substr(1));
            t.first = -t.first;
            t.second = -t.second;
        }else{
            t = f(s);
        }
        //cout << " " << t.first << " " << t.second << endl;
        ans1 += t.first;
        ans2 += t.second;
        //cout << ans1 << " " << ans2 << endl;
        while(ans2 < 0){
            ans1--;
            ans2 += geta;
        }
        while(ans2 >= geta){
            ans1++;
            ans2 -= geta;
        }
        //cout << " " << ans1 << " " << ans2 << endl;
    }
    if(ans1 < 0 && ans2 > 0){
        ans1++;
        if(ans1 == 0)cout << "-";
        ans2 = geta - ans2;
    }
    string ans = to_string(ans2);
    while(ans.size() < 10)ans = "0" + ans;
    cout << ans1 << "." << ans << endl;
}