A corporation has 100 types of customers from Type 1 to Type 100. For any customer Type N (where N varies from 1 to 100), the customer default rate is N% and the account receivable period is N months. If the gross profit margin of the business is 45%, and the cost of capital is 20% per annum. Out of the 100 types of customers, which are the types of customers with which A corporation would not like to do any business. Assume all cashflows due to profits from sales, and losses due to customer defaults occur at the end of the year 1.