Yammer API to get unread message count

Question

I want to get the count for Yammer Inbox's unread messages using the yammer REST API.

The documented messages are provided here: https://developer.yammer.com/restapi/#rest-messages

But unfortunately, I cannot find the unread count anywhere. Is there a specific tag in the response that provides this count?

Any help here is appreciated.

Update: By unread count, I mean a count of messages that haven't been checked yet. The yammer inbox tab shows this count. (See image at this link for reference. http://picpaste.com/pics/d-swJKH732.1393307190.png)