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

public class Yukicoder81 {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		BigDecimal res = new BigDecimal(BigInteger.ZERO);
		for (int i = 0; i < n; i++) res = res.add(new BigDecimal(sc.next()));
		System.out.printf("%.10f",res);
	}
}