#include<iostream>
#include<sstream>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<algorithm>
#include<string>
#include<vector>
#include<cmath>
#include<set>
#include<map>
#include<stack>
#include<queue>
#include<numeric>
#include<functional>
#include<complex>

using namespace std;
#define BET(a,b,c) ((a)<=(b)&&(b)<(c))
#define FOR(i,n) for(int i=0,i##_end=(int(n));i<i##_end;i++)
#define SZ(x) (int)(x.size())
#define ALL(x) (x).begin(),(x).end()
#define MP make_pair
#define FOR_EACH(it,v) for(__typeof(v.begin()) it=v.begin(),it_end=v.end() ; it != it_end ; it++)
typedef vector<int> VI;
typedef vector<VI> VVI;

long long parse(string s){
    long long v = 0 ;
    FOR(i,SZ(s)) v = v * 10 + (s[i] - '0');
    return v;
}

long long myabs(long long x){
    return max(x,-x);
}

int main()
{
    int N;
    cin>>N;
    long long integer = 0, decimal = 0;
    FOR(i,N){
        string s;
        cin>>s;
        int sign = 1;
        if(s[0] == '-') {
            sign = -1;
            s = s.substr(1);
        }
        auto dot = s.find('.');
        if(dot != string::npos){
            integer += sign * parse(s.substr(0, dot));
            string d = s.substr(dot + 1);
            d.resize(10, '0');
            decimal += sign * parse(d);
        }else{
            integer += sign * parse(s);
        }
    }
    long long carry = decimal / 10000000000LL;
    integer += carry;
    decimal %= 10000000000LL;
    bool minus = false;
    if(integer < 0 || (integer == 0 && decimal < 0)) minus = true;
    printf("%s%lld.%010lld", minus ? "-" : "",  myabs(integer), myabs(decimal));
    return 0;
}