public class MainClass {

    // 0 1 2 3 4 5 6 7 8 9
    // 10
    // 10 / 2 = 5
    // 5 - 1 = 4
    public static void main(String[] args) {

    }

    private static int[] changeByDomainLogic(int[] array) {
        if(checkIfArrayEven(array)) {
            array[0] = sumOfSecondPart(array);
        }
        return array;
    }

    private static int sumOfSecondPart(int[] array) {
        int sum  = 0;
        int mediumIndex = array.length / 2 - 1;
        for(int i = mediumIndex + 1; i < array.length; i++) {
            sum += array[i];
        }
        return sum;
    }

    private static boolean checkIfArrayEven(int[] array) {
        if(array.length == 0) return false;
        return array.length % 2 == 0;
    }
}