#include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for(ll i=0;i<n;i++)
#define repl(i,l,r) for(ll i=(l);i<(r);i++)
#define per(i,n) for(ll i=(n)-1;i>=0;i--)
#define perl(i,r,l) for(ll i=(r)-1;i>=l;i--)
#define fi first
#define se second
#define pb push_back
#define ins insert
#define pqueue(x) priority_queue<x,vector<x>,greater<x>>
#define all(x) (x).begin(),(x).end()
#define CST(x) cout<<fixed<<setprecision(x)
#define rev(x) reverse(x);
using ll=long long;
using vl=vector<ll>;
using vvl=vector<vector<ll>>;
using pl=pair<ll,ll>;
using vpl=vector<pl>;
using vvpl=vector<vpl>;
const ll MOD=1000000007;
const ll MOD9=998244353;
const int inf=1e9+10;
const ll INF=4e18;
const ll dy[9]={1,0,-1,0,1,1,-1,-1,0};
const ll dx[9]={0,-1,0,1,1,-1,1,-1,0};
template<class T> inline bool chmin(T& a, T b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}
template<class T> inline bool chmax(T& a, T b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}
int main(){
    ll r=0,p=0;
    ll n;cin >> n;
    while(n--){
        string s;cin >> s;
        bool flag=true;
        if(s[0]=='-')flag=false;
        int pls=-1;
        rep(i,s.size())if(s[i]=='.')pls=i;
        if(pls==-1){r+=stoll(s);continue;}
        string t,x;
        rep(i,pls)t+=s[i];
        r+=stoll(t);
        repl(i,pls+1,s.size())x+=s[i];
        while(x.size()<10)x+='0';
        if(flag)p+=stoll(x);
        else p-=stoll(x);
    }
    if(p<0&&r<0){
        p*=-1;
        r-=p/10000000000;
        p%=10000000000;
        string z=to_string(p);
        while(z.size()<10){
            z="0"+z;
        }
        cout << r <<'.' <<z <<endl;
        return 0;
    }
    if(p<0)r--,p+=10000000000;
    r+=p/10000000000;
    p%=10000000000;
    string z=to_string(p);
    while(z.size()<10){
        z="0"+z;
    }
    cout << r <<'.' <<z <<endl;
}