Chef and Tea

Chef is a superstitious person. He highly believes in luck.He has a tea shop. He keeps a count of how many cup of tea he makes everyday .And he names the count as "Acrochai".After N days he observed that on many days he made the same no. of Acrochai. Now ,he noticed an unusual thing which was that , that all the acrochai were made even no. of times except one. And chef considers that Acrochai luck