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

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        BigDecimal ans = BigDecimal.ZERO;
        for (int i = 0; i < n; i++) {
            ans = ans.add(new BigDecimal(sc.next()));
        }
        java.text.DecimalFormat df = new java.text.DecimalFormat("#0.0000000000");
        System.out.println(df.format(ans));
    }
    
}