<s>[INST] <<SYS>>
You are an expert in regular expressions (regex)
<</SYS>>

Find a regex pattern that matches the following string:
1991-09-28T05$3C56$3C59.345Z [/INST] pattern:
\d{4}\-\d{2}\-\d{2}T\d{2}\$3C\d{2}\$3C\d{2}\.\d{3}Z </s>