All in Python please:

1. Include a greet() function that does not take parameters or returns a value
2. The greet() function is to print a "Hello World!" message
3. Include an add() function that takes two parameters, num1 and num2, and adds them
4. The call of the add() function is to send the values of 4 and 5 as positional arguments
5. Include a city_country() function that takes two parameters, a city name and the country it's in
6. The city_country() function returns a string formatted like this: "Santiago, Chile"
7. Call the city_country function multiple times (at least 3x) with different city/country info