For every 4 ‘c’ in the input push a ‘c’ in the stack (Push down automata)

Given the following language: L = {$ a^{2m}$ $ c^{4n}$ $ d^{n}$ $ b^{m}$ : m,n >= 0} I’m trying to design a PDA. My aproach is:

-for every 2 ‘a’ push an ‘a’

-for every 4 ‘c’ push a ‘c’

-then pop them to solve the 2nd half of the language

This is the first part to count 2 ‘a’, but the ‘c’part is not very clear:enter image description here

Any hints or solutions for the problem: ‘’for every 4 ‘c’ push a ‘c’ on the stack‘’