package no81;

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

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		BigDecimal sum = BigDecimal.ZERO;
		for(int i=0;i<n;i++) {
			sum = sum.add(new BigDecimal(sc.next()));
		}
		String s = sum.toPlainString();
		if (s.indexOf('.') >= 0) {
			System.out.println(s + ("0000000000".substring(Math.min(10,-s.indexOf('.')+s.length()-1))));
		}else{
			System.out.println(s + ".0000000000");
		}
	}
}