Let \( \mathrm{U}=\{1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20\} \), \( C=\{1,3,5,7,9\} \).
Use the roster method to write the set \( \mathrm{C}^{\prime} \).
\[
C^{\prime}=\{\square
\]
(Type all of the elements. Use a comma to separate answers as needed. Use ascending order.)