import java.math.BigDecimal;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        try (Scanner scan = new Scanner(System.in)) {
            int n = Integer.parseInt(scan.next());
            BigDecimal sum = BigDecimal.ZERO;
            for(int i=0; i<n; i++) {
                sum = sum.add(scan.nextBigDecimal());
            }
            System.out.println(sum.setScale(10));
        }
    }
}