how to remove array keys and double quotes from array in php?

In an array i have key and its value in double quotes like this

$a = [

0 => "19 => 0"
  
1 => "20 => 0"
 
2 => "21 => 0"
  
3 => "24 => 18.831126689097"
  
4 => "25 => 0"
  
5 => "26 => 0.85071506409078"]

i want output delete all keys and double quotes how i can do that in php?

19 => 0
  
20 => 0
 
21 => 0
  
24 => 18.831126689097
  
25 => 0
  
26 => 0.85071506409078

via Chebli Mohamed