import java.util.*;

public class Gardener {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        try {
            int n = sc.nextInt();

            // If n is zero or negative → invalid
            if (n <= 0) {
                System.out.println("Invalid input");
                return;
            }

            int sum = 0;
            for (int i = 0; i < n; i++) {
                int value = sc.nextInt();
                if (value % 2 == 0) { 
                    sum += value;
                }
            }

            System.out.println(sum);

        } catch (Exception e) {
            System.out.println("Invalid input");
        }
    }
}