Insert a line of code that defines and prints a string containing the words "Hello, world!”
```python
my_string = "Hello, world!"
print(my_string)
```
Complete the following task based on the instruction and optional input provided.### Instruction:
Insert a line of code that defines and prints a string containing the words "Hello, world!”

### Output:
```python
my_string = "Hello, world!"
print(my_string)
```