static wordcount_t vli_numDigits(const uECC_word_t *vli, const wordcount_t max_words) {
    wordcount_t i;
    /* Search from the end until we find a non-zero digit.
       We do it in reverse because we expect that most digits will be nonzero. */
    for (i = max_words - 1; i >= 0 && vli[i] == 0; --i) {
    }

    return (i + 1);
}