Get value from nested list of map with string and atom keys

I have this list of maps:

 [
%{
"$value" => %{"$sum": %{"id" => 2}},

 },
%{
"$value" => %{"$sum": %{"id" => 1}},
}
]

I need to get the id value. The problem is with the $sum key, which is an atom.

How I can I fetch it for both of the above maps.
Thanks.