Table:
Sandwich	Number of customers

Roast beef	810

Egg salad	780

Ham	950

Other	780

How many rows and columns does this table contain? Output the final answer as JSON in the format {"row_number": "m", "column_number": "n"}.

There are 6 rows and 2 columns in the table. So, the final answer is {"row_number": "6", "column_number": "2"}.