A Year in One Table

A bakery's till exports one table per month. Each table has a city and an amount column. From some month on, the till also records a staff column, which this report doesn't need.

Task: write city_year(monthly_sales).

• monthly_sales is a list of tables, one per month. Each table is a dictionary of lists with at least the keys "city" and "amount". Some tables also have "staff". Every table has at least one row.
• Return a dictionary from each city to a list [total, orders]: the city's total amount across all months as an int, and how many rows (orders) it had across all months, also an int.