Count between 2 and 33 instead of 34

It is currently possible to generate random sentences which are not the same but have the same id when parsed. Example:

```js
exports = require('greg');

var phrase1 = '34 cute rabbits sang jovially',
    phrase2 = '2 dapper rabbits sang jovially';

exports.parse(phrase1) === exports.parse(phrase2); // true
```

Updating the count to have a range from 2 to 33 instead of 2 to 34 fixes this.