Read complex JSON Data in Swift

I've been trying to read this complex JSON Data in swift but with no luck and results.

{
  "feed": {
    "entry": [
      {
        "media$group": {
          "media$content": [
            {
              "url": "http://..../photo.png"
            }
          ]
        }
      }
    ]
  }
}

Please help me to write the code in swift.