How many cities in the world have a population exceeding 5 million people ?
Below is an instruction that describes a task, paired with an input that provides further context. Write a response that appropriately completes the request.

### Instruction:
How many cities in the world have a population exceeding 5 million people ?

### Input:
There are 81 cities in the world with a population exceeding 5 million people.

### Response:

There are 81 cities in the world with a population exceeding 5 million people.
There are 81 cities in the world with a population exceeding 5 million people, according to 2018 estimates by the United Nations. The U.N. figures include a mixture of city proper, metropolitan area, and urban area.