The Coffee Machine At Work

While getting coffee at work, I came across this interesting little problem. The coffee machine gives us two size options - 'Regular' and 'Medium'. I know one option fills my cup, the other option causes it to overflow. My dilemma is choosing the correct option, so my cup doesn't overflow. Of the two options, does Regular imply the larger size and Medium the smaller size? Or does Regular imply the smaller size? I have no way to tell.




If either of the two words were substituted by 'Small' or 'Large', I would have known which option to choose. For example, Between Large and Regular, I know the large size would provide more coffee. Similarly, if I had to choose between Regular and Small, I would assume Regular would provide more coffee than Small. The same reasoning applies for Large/Medium or Medium/Small. Of all the permutations using the four words (i.e., Large, Medium, Small and Regular), the coffee machine provides the only combination that makes it impossible to figure out the dispensing amount. By the way, for this particular coffee machine, I found out that Regular is larger than Medium.