Punishing a sub with a spanking and corner time

A Dom is punishing his/her sub for breaking a rule. However, he/she wants to give the sub some flexability in the punishment. Here are the terms of the punishment:

1) The sub receives m strokes with a paddle on bare bottom.

2) The sub spends n minutes in the corner after the spanking

The sub can pick any values for n and m such that n and m are integers, m >= 0, n >= 0, and n + m = 20. What values should the sub pick to minimize the punishment?

Why minimize? M=19, N=1 are my values.

The argument for minimization is that when a person is being punished, they want to minimize the punishment they receive. That is certainly true in most real life cases such as criminals. I have also found it to be often true when it came time to punish a girlfriend.