[nicolaslegland]

https://regex.inginf.units.it/ only needed 5 seconds to generate /(?<=Rd )\d++/ when I highlighted 9856, 10190, 9753 and 8883.

https://regex.ai/ was stuck with /9856|10190|9753|8883/ and confidently emitted /\d{4}/ as an alternative.

https://regex101.com/r/cAaV1z/1 confirms the former.