This question is ambiguous. The time to count to 1 million could be more or less then 23 days. However, if someone counted to 1 million in 23 days nonstop, the interval between saying the next number would be 2 seconds.
See here for more information. https://www.quora.com/How-long-does-it-take-to-count-to-one-million
DOCK
HIKE
CHOKE
FISH does not work because the S is not horizontally symmetric.
BONE doesn't work because the N is not horizontally symmetric.
Answer:
98-54+12-36
110-54-36
56-36
20<em>A</em><em>n</em><em>s</em>
