I need to add an user called "admin". When I type:

```
# adduser admin

```

I get:

```
adduser: The group 'admin' already exists.

```

So, I guess, by default, `adduser` is trying to create an "admin" group that already exist at the same time as creating the "admin" user. Reading adduser man page I've seen `-N` option to avoid goup creation. I tried this:

```
adduser -N admin

```

With the same result. How can I create an "admin" user?