Question from the Java test

Given the following code :

private static Integer[] myCompute(int a) {
    int i = 0;
    Integer[] result = new Integer[2];
    result[i++] = new Integer(a);
    result[i] = new Integer(-a);
    result[1 - i] = result[i];
    return result;
}

After calling :

Integer[] call = myCompute(3);

How many instance of Integer cannot be freed from memory?