#include <bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for(int i=a;i<b;i++)

typedef long long ll;

ll solve(string s)
{
	int i = 0;
	ll minus = 1;
	if (s[i] == '-')
	{
		minus = -1;
		i++;
	}

	ll ret = 0;
	while (i < s.length())
	{
		if (s[i] == '.') break;
		ret = ret * 10 + s[i] - '0';
		i++;
	}

	rep(i, 0, 10) ret *= 10;
	if (i == s.length()) return minus * ret;

	i++;
	ll d = 1;
	rep(i, 0, 9) d *= 10;
	while (i < s.length())
	{
		ret += (s[i] - '0') * d;
		d /= 10;
		i++;
	}

	return minus * ret;
}

int main()
{
	/*cout << solve("123.123") << endl;
	return 0;*/

	int N; cin >> N;
	
	ll sum = 0;
	rep(i, 0, N)
	{
		string s; cin >> s;
		sum += solve(s);
	}

	string ans = to_string(sum);
	rep(i, 0, ans.length() - 10) cout << ans[i];
	cout << ".";
	rep(i, ans.length() - 10, ans.length()) cout << ans[i];
	cout << endl;
}