Table:
Athlete	Event	Heat	Semifinal	Final

Time	Rank	Time	Rank	Time	Rank

Christopher Duenas	100 m freestyle	53.37	44	Did not advance

Benjamin Schulte	10 km open water	N/A	2:03:35.1	25

Examine the table in this image and extract any merged cell regions. Please format the merged cell regions as JSON {'top-left':(R1, C1), 'bottom-right':(R2, C2)}, with (R1, C1) indicating the (row_id, column_id) of the top-left cell and (R2, C2) the bottom-right cell in the merged regions. Remember that the R1, C1, R2, C2 all start from 1.

The merged cell regions are as follows:
{'top-left':(1, 1), 'bottom-right':(2, 1)}
{'top-left':(1, 2), 'bottom-right':(2, 2)}
{'top-left':(1, 3), 'bottom-right':(1, 4)}
{'top-left':(1, 5), 'bottom-right':(1, 6)}
{'top-left':(1, 7), 'bottom-right':(1, 8)}
{'top-left':(3, 5), 'bottom-right':(3, 8)}
{'top-left':(4, 3), 'bottom-right':(4, 6)}.