I want that the usernames be 4-32 chars long.

```
function validate_username($input)
{
    return (bool) preg_match('/^([a-z]+[a-z0-9_]*){4,32}$/i', $input);
}

```

What is wrong with my try, please?

`var_dump(validate_username('h_q8Y'));` which returns `FALSE`

But `var_dump(validate_username('h_q8Yewre_'));` returns `TRUE`