How to get the value from this Hash?

"accounts": {
"data": [
  {
    "posts": {
      "data": [
        {
          "id": "76917571976", 
          "created_time": "2015-03"
        }, 
        {
          "id": "76917571976118", 
          "created_time": "2014-09-07"
        }, 
        {
          "id": "76917571976", 
          "created_time": "2014-04-15"
        }, 
        {
          "id": "7691757197611", 
          "created_time": "2014-04-11"
        }, 
        {
          "id": "76917571976118", 
          "created_time": "2014-03-11"
        }
      ], 
      "paging": {
        "previous": "https//facebook.com", 
        "next": "http://ift.tt/wljqS4"
      }
    }, 
    "id": "12343"
  }
]

I have been trying the get the value of the "id": attribute inside "data": . I am using the graph api to get the id of a post The code I am using is ['accounts']['data'][0]['posts'][0]['id] but it's giving an error

undefined method `[]' for nil:NilClass

which obviously is due the fact that it's not able to retrieve any value from the graph api.

Can somebody help me with this, thank you in advance.