private int GetNumberOfOccurrence(PasswordPolicyDay2b policy)
        {
            var numberOfOccurrencesAtPositions = 0;

            foreach (var occ in policy.Occurrences)
            {
                if (policy.Password.ElementAt(occ - 1).ToString() == policy.Letter)
                {
                    numberOfOccurrencesAtPositions += 1;
                }
            }
            return(numberOfOccurrencesAtPositions);
        }
        private bool ChekIfPolicyWorks(PasswordPolicyDay2b policy)
        {
            var occurrences = GetNumberOfOccurrence(policy);

            return(occurrences == 1);
        }