Accessing a Key in JSON Response
===

How in the following JSON response can I check if **uids** is nil ?
   
    {
    height = 480;
    pid = "F@dd705e6b96a6e894556c0db84870501e_d97383cc80238c38b8907d99690fa1c9";
    tags =     (
                {
            attributes =             {
                glasses =                 {
                    confidence = 97;
                    value = false;
                };
                smiling =                 {
                    confidence = 97;
                    value = false;
                };
            };
            center =             {
                x = "60.83";
                y = "75.21";
            };
            gid = "<null>";
            height = "49.58";
            label = "";
            manual = 0;
            nose =             {
                x = "76.21";
                y = "77.16";
            };
            pitch = "-5.55";
            recognizable = 0;
            roll = "-0.45";
            uids =             (          <<<<<========== UIDs Key
            );
            width = "66.11";
            yaw = "-19.56";
        }
    );
    url = "http://face.com/images/ph/a6e529853432599dad6da996746cb070.jpg";
    width = 360;
    }

When I try :

    if ([[[[photo objectForKey:@"tags"] objectAtIndex:0] valueForKey:@"uids"] count] == 0)

It keeps returning FALSE all the time. 

What am I doing wrong ?