#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<long long,long long> pll;
#define ep emplace_back
#define pb push_back
#define mp make_pair
#define rep(i,n) for(int i=0;i<(n);++i)
constexpr int mod=1000000007;
constexpr int mod1=998244353;
vector<int> dx={0,1,0,-1},dy={-1,0,1,0};
bool inside(int y,int x,int h,int w){
	if(y<h && y>=0 && x<w && x>=0) return true;
	return false;
}





int main(){
	cin.tie(0);
	ios::sync_with_stdio(false);
	int n;cin >> n;
	ll ans1 = 0, ans2 = 0;
	rep(i,n){
		string a;cin >> a;
		ll b = 0, c = 0, k = 1e9;
		bool flg = true, mi = false;
		rep(j,a.size()){
			if(j == 0 && a.at(0) == '-'){
				mi = true;
				continue;
			}
			if(a.at(j) == '.'){
				flg = false;
				continue;
			}
			if(flg){
				b *= 10;
				b += a.at(j) - '0';
			}
			else{
				c += (a.at(j) - '0') * k;
				k /= 10;
			}
		}
		if(mi){
			b *= -1;
			c *= -1;
		}
		ans1 += b;
		ans2 += c;
	}
	ans1 += ans2 / 10000000000;
	ans2 %= 10000000000;
	cout << ans1 << ".";
	cout << setfill('0') << right << setw(10) << ans2 << endl;
}