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

public class Main {
	
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		
		final int N = sc.nextInt();
		
		BigDecimal answer = BigDecimal.ZERO;
		for(int i = 0; i < N; i++){
			answer = answer.add(new BigDecimal(sc.next()));
		}
		answer = answer.setScale(10, BigDecimal.ROUND_HALF_UP);
		
		System.out.println(answer.toString());
	}
	
}