#include<iostream>
#include<string>
using namespace std;
typedef long long ll;

int main(){
    int n;
    ll accum = 0;

    cin >> n;

    string a;
    for(int i = 0; i < n; i++){
        cin >> a;
        int dotpos;
        for(dotpos = 0; dotpos < a.length(); dotpos++)  if(a[dotpos] == '.')    break;
        ll val;
        if(dotpos == a.length()){
            val = stoll(a) * 10000000000;
        }else{
            int residual = 10;
            while(dotpos != a.length()-1){
                swap(a[dotpos], a[dotpos+1]);
                residual--;
                dotpos++;
            }
            val = stoll(a.substr(0, a.length()-1));
            while(residual-- > 0)   val *= 10;
        }
        accum += val;
    }

    bool minus = accum < 0;

    accum = abs(accum);

    string decimal = "";
    for(int i = 0; i < 10; i++){
        int digit = accum % 10;
        decimal = (char)('0' + digit) + decimal;
        accum /= 10;
    }

    cout << (minus ? "-" : "") << accum << "." << decimal << endl;

    return 0;
}