import java.util.*;
import java.math.*;
 
public class Main {
    //MathContext AA = new MathContext(100, RoundingMode.HALF_UP);
    void run() {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        BigDecimal a = new BigDecimal("0"/*,AA*/);
        for( int i = 0; i < n; i++ ) {
            BigDecimal p = sc.nextBigDecimal();
            a = a.add(p);
        }
        //System.out.printf("%.10f\n",a.doubleValue());
        System.out.println(a.setScale(10).toPlainString());
    }
    public static void main(String[] z) {
        new Main().run();
    }
}