#include "bits/stdc++.h"
#define REP(i,n,N) for(ll i=(n); i<(N); i++)
#define RREP(i,n,N) for(ll i=(N-1); i>=n; i--)
#define CK(n,a,b) ((a)<=(n)&&(n)<(b))
#define ALL(v) (v).begin(),(v).end()
#define p(s) cout<<(s)<<endl
#define p2(a,b) cout<<(a)<<" "<<(b)<<endl
#define v2(T) vector<vector<T>>
typedef long long ll;
using namespace std;
const ll mod= 1e10;

int N;
ll suma, sumb;
int main(){
    cin>>N;
    REP(i,0,N){
        string a;
        cin>>a;
        int now=0;
        ll tmpa=0, tmpb=0;
        bool c=false;
        if(a[0]=='-'){
            c=true;
            now++;
        }
        REP(i,now,a.size()){
            if(a[i]=='.') {
                now++;
                break;
            }
            tmpa*=10;
            tmpa+=a[i]-'0';
            now++;
        }
        int keta=0;
        REP(i,now,a.size()){
            tmpb*=10;
            tmpb+=a[i]-'0';
            keta++;
        }
        REP(i,0,10-keta){
            tmpb*=10;
        }

        if(c){
            tmpa=-tmpa;
            tmpb=-tmpb;
        }

        sumb+=tmpb;
        suma+=tmpa;
    }
    suma += sumb / mod;
    sumb %= mod;

    if (suma == 0 && sumb < 0){
        cout << "-";
        sumb *= -1;
    }

    if (suma < 0){
        if (sumb <= 0){
            sumb *= -1;
        }
        else{
            suma++;
            sumb -= mod;
            sumb *= -1;
            if (suma == 0) cout << "-";
        }
    }
    else{
        if (sumb < 0){
            suma--;
            sumb += mod;
        }
    }

    printf("%lld", suma);
    printf(".");
    printf("%010lld\n", sumb);
    return 0;
}