private static int getValueAt(String binaryNumber, int index) {
        int value = binaryNumber.charAt(index) - 48;
        if (value < 0 || value > 1) {
            throw new IllegalArgumentException(
                    "Error parsing input data, review your parameters, should be a valid binary number!");
        }
        return value;
    }
We are going to subtract 48 to the char to get the number value from the String. This is
going to work because the char set we are using is ASCII.
src/main/java/com/github/pedrovgs/problem3/SumBinaryNumbers.java