How can I combine 2 PDA’s into 1


I need to form PDA for this language: {$ a^nb^m|n=m \vee n=2m$ }

I know the idea of building each one separately but how do I combine them into 1 PDA?

LHS: for every ‘a’ I push ‘A’ inside stack and for every ‘b’ I eject ‘A’.

RHS:for every ‘a’ I push ‘A’ inside stack and for every ‘b’ I eject 2 times ‘A’.

How can I combine them? Can I somehow use non determinism?