import java.util.*;
import java.math.BigDecimal;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner koko = new Scanner(System.in);
        int n = koko.nextInt();
        BigDecimal total= new BigDecimal("0.0000000000");
        BigDecimal[] a = new BigDecimal[n];
        for(int i=0; i<n; i++){
            a[i]= new BigDecimal(koko.next());
            total = total.add(a[i]);
        }
        System.out.printf("%.10f",total);
    }
}