import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String[] inputString = sc.nextLine().split(" ");
        int currentBiggest = 0;
        int biggestEven = 0;
        boolean isANumber = false;
        String holdingString;
        int holdingInt = 0;
        for (int i = 0; i < inputString.length; i++) {
            holdingString = inputString[i];
            for (int j = 0; j < holdingString.length(); j++) {
                if (holdingString.charAt(j) >= 48 && holdingString.charAt(j) <= 57) {
                    isANumber = true;
                } else {
                    isANumber = false;
                    break;
                }

            }
            if (isANumber) {
                if (Integer.parseInt(holdingString) % 2 == 0) {
                    currentBiggest = Integer.parseInt(holdingString);
                }
                if (biggestEven < currentBiggest) {
                    biggestEven = currentBiggest;
                }
            }
        }
        System.out.println(biggestEven);
    }
}