#include "bits/stdc++.h"
using namespace std;
     
#define DEBUG(x) cout<<#x<<": "<<x<<endl;
#define DEBUG_VEC(v) cout<<#v<<":";for(int i=0;i<v.size();i++) cout<<" "<<v[i]; cout<<endl
     
typedef long long ll;
#define vi vector<int>
#define vl vector<ll>
#define vii vector< vector<int> >
#define vll vector< vector<ll> >
#define vs vector<string>
#define pii pair<int,int>
#define pis pair<int,string>
#define psi pair<string,int>
const int inf = 1000000001;
const ll INF = 1e16;
#define MOD 1000000007
#define mod 1000000009
#define pi 3.14159265358979323846
#define Sp(p) cout<<setprecision(15)<<fixed<<p<<endl;
int dx[4] = { 1,0,-1,0 }, dy[4] = { 0,1,0,-1 };
int dx2[8] = { 1,1,0,-1,-1,-1,0,1 }, dy2[8] = { 0,1,1,1,0,-1,-1,-1 };


int main() {
  int n, i, j;
  cin >> n;
  vs sei, fu;
  for (i = 0; i < n; i++) {
    string s;
    cin >> s;
    if (s[0] == '-') {
      fu.push_back(s);
    }
    else {
      sei.push_back(s);
    }
  }
  vi sumsei(31); //sum[30]が小数第10位、sum[20]が1の位、sum[19]が10の位 
  for (i = 0; i < sei.size(); i++) {
    string b = "?";
    for (j = 0; j < sei[i].size(); j++) {
      if (sei[i][j] == '.') {
	b = sei[i].substr(j + 1, sei[i].size() - j - 1);
	sei[i] = sei[i].substr(0, j);
      }
    }
    for (j = sei[i].size() - 1; j >= 0; j--) {
	sumsei[21 - sei[i].size() + j] += sei[i][j] - '0';
    }
    if (b != "?") {
      for (j = 0; j < b.size(); j++) {
	sumsei[21 + j] += b[j] - '0';
      }
    }
  }
  vi sumfu(31);
  for (i = 0; i < fu.size(); i++) {
    string b = "?";
    fu[i].erase(fu[i].begin());
    for (j = 0; j < fu[i].size(); j++) {
      if (fu[i][j] == '.') {
	b = fu[i].substr(j + 1, fu[i].size() - j - 1);
	fu[i] = fu[i].substr(0, j);
      }
    }
    for (j = fu[i].size() - 1; j >= 0; j--) {
	sumfu[21 - fu[i].size() + j] += fu[i][j] - '0';
    }
    if (b != "?") {
      for (j = 0; j < b.size(); j++) {
	sumfu[21 + j] += b[j] - '0';
      }
    }
  }

  //DEBUG_VEC(sumsei);
  //DEBUG_VEC(sumfu);
  
  for (i = 0; i < 31; i++) {
    sumsei[i] -= sumfu[i];
  }
  for (i = 30; i >= 0; i--) {
    if (sumsei[i] < 0) {
      int cnt = sumsei[i] / 10 + 1;
      sumsei[i - 1] -= cnt;
      sumsei[i] += 10 * cnt;
    }
    else if (sumsei[i] >= 10) {
      int cnt = sumsei[i] / 10;
      sumsei[i] -= cnt * 10;
      sumsei[i - 1] += cnt;
    }
  }
  string s;
  for (i = 0; i < 31; i++) {
    s.push_back(sumsei[i] + '0');
    if (i == 20) {
      s.push_back('.');
    }
  }
  while (s[0] == '0') {
    s.erase(s.begin());
  }
  if (s[0] == '.') {
    s = '0' + s;
  }
  cout << s << endl;
}