# Hints

## 1. Generate seat letters

- The returned value should be of _type_ `generator`.
- You can have a sequence of letters from `A` to `D` and cycle through them.
- Use `yield` to return the next letter.

## 2. Generate seats

- The returned value should be of _type_ `generator`.
- Row `13` should be skipped, so go from `12` to `14`.
- Keep in mind that the returned values should be ordered from low to high. `1A, 1B, 2A, ...`
- Here it might be good to reuse or call functions you have already defined.

## 3. Assign seats to passengers

- Make sure your seat numbers do not have any spaces in them.
- Here it might be good to reuse or call functions you have already defined.

## 4. Ticket codes

- You can use `len()` to get the length of a string.
- You can use `"<string>" * <int>` to repeat a string.