I have data formatted like this:

```
a cat
a dog
brown cat
brown dog
brown cow
brown sheep
brown fish

```

I want to filter out all of the lines starting with "brown", except `brown dog`. Is there an easy way to do this with grep or awk? I tried to use the carat negation like so:

```
grep -v "brown ^\(dog\)" corpus.txt

```

... but that didn't work. Any ideas would be greatly appreciated.

Eventually I want the output to be like this:

```
a cat
a dog
brown dog

```