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

Find a regex pattern that matches the following string:
1991%3C05%3C09+11:44:23 [/INST] pattern:
\d{4}%3C\d{2}%3C\d{2}\+\d{2}:\d{2}:\d{2} </s>