Filter for non-repeated values based on Unique ID

Question

I've the following table

S/N	Unique ID	Code
1	111	YES
2	111	YES
3	111	NO
4	111	YES
5	222	YES
6	222	YES
7	222	YES
8	222	YES
9	333	NO
10	333	NO
11	333	YES
12	333	YES

How do I derive the following table based on the following conditions: For each unique ID, if YES repeats, keep the first YES. If NO Appears, keep the following YES. I tried using mutate and it's giving me all sort of errors.

S/N	Unique ID	Code
1	111	YES
4	111	YES
5	222	YES
11	333	YES

Thanks!