#include <bits/stdc++.h>

using namespace std;
typedef long long ll;
typedef pair<ll, ll> p_ll;

template<class T>
void debug(T itr1, T itr2) { auto now = itr1; while(now<itr2) { cout << *now << " "; now++; } cout << endl; }
#define repr(i,from,to) for (int i=(int)from; i<(int)to; i++)
#define all(vec) vec.begin(), vec.end()
#define rep(i,N) repr(i,0,N)
#define per(i,N) for (int i=(int)N-1; i>=0; i--)

const ll MOD = pow(10,9)+7;
const ll LLINF = pow(2,61)-1;
const int INF = pow(2,30)-1;

vector<ll> fac;
void c_fac(int x=pow(10,6)+10) { fac.resize(x,true); rep(i,x) fac[i] = i ? (fac[i-1]*i)%MOD : 1; }
ll inv(ll a, ll m=MOD) { ll b = m, x = 1, y = 0; while (b!=0) { int d = a/b; a -= b*d; swap(a,b); x -= y*d; swap(x,y); } return (x+m)%m; }
ll nck(ll n, ll k) { return fac[n]*inv(fac[k]*fac[n-k]%MOD)%MOD; }
ll gcd(ll a, ll b) { if (a<b) swap(a,b); return b==0 ? a : gcd(b, a%b); }
ll lcm(ll a, ll b) { return a/gcd(a,b)*b; }


int main() {
  ll N; cin >> N;
  string A[N]; rep(i,N) cin >> A[i];
  vector<int> u[N], d[N];
  vector<bool> isp(N,true);
  rep(i,N) {
    bool isu = true;
    rep(j, A[i].size()) {
      if (A[i][j]=='-') isp[i] = false;
      else if (A[i][j]=='.') isu = false;
      else {
        if(isu) u[i].push_back(A[i][j]-'0');
        else d[i].push_back(A[i][j]-'0');
      }
    }
    while (u[i].size()<10) u[i].insert(u[i].begin(),0);
    while (d[i].size()<10) d[i].push_back(0);
  }
  // rep(i,N) { cout << (isp[i] ? "+" : "-"); rep(j,10) cout << u[i][j]; cout << "."; rep(j,10) cout << d[i][j]; cout << endl; }

  ll us = 0, ds = 0;

  rep(i,N) {
    ll un = 0, dn = 0;
    rep(j,10) {
      un *= 10; un += u[i][j];
      dn *= 10; dn += d[i][j];
    }
    if (isp[i]) { us += un; ds += dn; }
    else { us -= un; ds -= dn; }
  }
  // cout << us << " " << ds << endl;

  ll dig = pow(10,10);
  if (ds>=0) {
    if (us+ds/dig>=0) {
      cout << us + ds/dig << ".";
      cout << setfill('0') << right << setw(9) << ds%dig;
      cout << endl;
    }
    else {
      cout << "-" << -1*(us+(ds+dig-1)/dig) << ".";
      cout << setfill('0') << right << setw(9) << dig-ds%dig;
      cout << endl;
    }
  }
  else {
    if (us+ds/dig>0) {
      cout << us + ds/dig - 1 << ".";
      cout << setfill('0') << right << setw(9) << dig+ds%dig;
      cout << endl;
    }
    else {
      cout << "-" << -1*(us+ds/dig) << ".";
      cout << setfill('0') << right << setw(9) << -1*ds%dig;
      cout << endl;
    }
  }
  return 0;
}