total a unique count

Hi, How can I get a total of distinct counts?  In this example 39 orders were written in both Jan and Feb in Japan. However in Jan 8 individual salespeople wrote orders,  In Feb 7 individual salespeople wrote orders.  How can I get those numbers to show?  The orders table is a detail containing order date which I've flipped to YYYY/MM.  I don't want a total of all the orders but rather the number of salespeople who wrote orders.  I've tried a number of combinations of summarize and filter without success.  Any help? 

By order count:

By distinct count: