Remove characters not desired in a field

Hello.

I need to get from a Text Fiel in a table a number inside.

The field contains that: 

{"op":"&","c":[{"type":"date","d":">=","t":1480582800},{"type":"group"}],"showc":[true,true]}

I need only the number. I can't remove {} [] characters, I've been using Replace operator to remove the other characters.

How can I do to extract the number and remove {}[] characters? Is there other way to extract the number without Replace operator?