# Understanding the CIP configuration for cyclic substituents with hetero-oxygen atoms

As per CIP sequence rules, the topmost $\ce{C}$ on the left gets 1st priority. Moving on to the right side of the double bond, we have:

Top $\ce{C}$: ($\ce{C}$,$\ce{O}$,$\ce{O}$,$\ce{H}$)
Bottom $\ce{C}$: ($\ce{C}$,$\ce{O}$,$\ce{O}$,$\ce{H}$,$\ce{C}$...)

Thus bottom $\ce{C}$ gets priority one on the right side.

Now, since 1st priorities are opposite, it's an E isomer. But the solution manual states that it's a Z isomer. Why is my method incorrect?